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Interim meeting

Scientific Research Working Group

Pisa, Auditorium dell’Opera della Primaziale Pisana, Piazza Arcivescovado

7-8 October 2010

BOOK OF ABSTRACTS

 

 

 

 

 

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ICOM-CC (International Council of Museums Committee for Conservation) is the largest of the

International Committees of ICOM with over 1800 members worldwide from every branch of the museum

and conservation profession. ICOM-CC aims to promote the investigation, analysis and conservation of

culturally and historically significant works and to further the goals of the conservation profession. ICOM-CC

is built up of specialist Working Groups, which actively communicate with their members through newsletters,

meetings and at the Triennial Conference. The Scientific Research Working Group is a venue to discuss in

detail new research technologies and methodologies across many types of materials and collections.

The ICOM CC Scientific Research Working Group Interim Meeting

Heritage Science is an interdisciplinary domain in which sciences such as physics, environmental

science, conservation science, computer science, material science, biology, chemistry, and other

fundamental sciences, converge with arts and humanities. Mainly because of its multidisciplinary nature,

publications and presentations to conferences are normally scattered across several disciplines and sub-

disciplines. The Interim Meeting of the Scientific Research Working Group will gather leading scientists in the

field offering an opportunity to both members of the Scientific Research Working Group, as well as to all

others interested in conservation oriented scientific research, to share knowledge and exchange ideas in

such an exciting field.

The meeting will focus on four grand challenges currently facing heritage sciences, and which are strongly interdependent: 1- characterisation, interpretation and understanding of heritage materials and objects, 2- advancement of analytical technologies, 3- understanding of material degradation, and 4- development of methods for stabilization, monitoring, and repair.

We would like to invite you to attend the interim meeting of the International Council of

Museums Committee for Conservation Scientific Research Working Group. The meeting,

organised in collaboration with ICOM Italia, will be held in Pisa, at the Auditorium of Opera della

Primaziale Pisana, alongside the UNESCO world heritage site of Piazza dei Miracoli, 7-8 October

2010. We look forward to meeting you all in Pisa in an informal atmosphere where we can discuss

the latest developments and applications in Heritage Science.

Ilaria Bonaduce, Organiser, Assistant Coordinator of ICOM CC SRWG

Cecily M. Grzywacz, Coordinator of ICOM CC SRWG

Bronwyn Ormsby, Assistant Coordinator of ICOM CC SRWG

Christoph Herm, Assistant Coordinator of ICOM CC SRWG

Matija Strlič, Assistant Coordinator of ICOM CC SRWG

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Index

Understanding Material Degradation 9

Aldo Romani, Catia Clementi, Chiara Grazia, Costanza Miliani: Photophysics of ancient anthraquinone-Al complexes: from the laboratory to the artwork 10

Valentina Pintus, Shuya Wei, Manfred Schreiner: Comparison of Single Shot and Double Shot Technique of Py-GC/MS for ageing studies of modern paint materials 12

Katrien Keune: Degradation of Emerald green in Descente des vaches (1834-35) by Theodore Rousseau: an analytical study 14

Gabriella Leo, Piero Pucci, Gennaro Marino, Leila Birolo, Laura Cartechini, Antonio Sgamellotti, Ilaria Bonaduce, Alessia Andreotti, Maria Perla Colombini: What can proteomics do for cultural heritage? 15

I. Bonaduce, L. Carlyle, M. P.Colombini, C. Duce, C. Ferrari, R. Mazzeo, S. Prati, E. Ribechini, P. Selleri, M.R. Tiné, E. Tombari, J. H.Townsend: Study on binding media in oil paintings: characterisation of linseed oil by DEMS, TGA and GC-MS 16

Aviva Burnstock,, Klaas Jan van den Berg, Suzan de Groot, Laura Hinde: Characterization of efflorescence on 20th Century oil paintings – an analytical study 18

Marianne Odlyha, Laurent.Bozec, Réne Larsen,Terje Grontoft: Evaluation of accelerated aged studies on cultural heritage objects organic in origin, in particular parchment and artists' varnishes 20

Characterising, Interpreting and Understanding Heritage Materials and Objects 21

M.P. Colombini, I. Degano, F. Modugno, E. Ribechini, M. Rocchi: Analytical study of ancient pharmaceutical preparations 22

Francesca Caterina Izzo, Klaas Jan Van Den Berg, Henk Van Keulen, Rossano Piazza, Guido Biscontin: An analytical survey on formulations of 20th Century oil paints 23

Ursula Baumer, Patrick Dietemann, Irene Fiedler, Jeanine Walcher: Developments in the technique of early oil painting in Germany (c. 1330-1530) 24

Vanessa Henriques Antunes, Orlando Anunciação: A data mining analysis over a database of materials of Portuguese painting from the 15th and 16th centuries 25

Václav Pitthard, Susanne Käfer, Silvia Miklin-Kniefacz, Marta Anghelone, Martina Griesser, Sabine Stanek: Technical study of varnishes from the collection of antique furniture belonging to the Prince of Liechtenstein 27

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Anabelle Križnar: Authentication of wall paintings made by the Older Villach’s Workshop on bases of material and technique analysis 29

Tomas Markevicius: The Invisible Story of Esther: unveiling an extraordinary collaboration between Sandro Botticelli and Filippino Lippi in two 15th Century Cassoni. Comparative technical study of new findings with InGaAs IR Reflectography 30

Annelies van Loon, Katrien Keune: Backscattered-electron images of paint cross-sections, an information source for tracing paint defects 31

D. Goodburn-Brown, E.G. Godfrey, W. Kockelmann, and A.M. Paradowska: X-radiography, 3D point to point and laser scanning for reconstruction and Neutron Diffraction analysis of 1st century High status Roman bronzes excavated from 3 burials in Kent, England 33

C.Miliani, K.J. van den Berg, B.G.Brunetti, Suzan de Groot, M. Vagnini, Matthijs de Keijzer, Henk van Keulen, Luc Megens, A.Sgamellotti, M.R. van Bommel: Non-invasive investigation vs. micro-destructive analysis: the case of Mondrian’s Victory Boogie Woogie 34

Developing Methods for Material Stabilization, Monitoring, and Repair 35

G. Botticelli, D. Carson, G. Chiari, F. Fratini, M. Matteini: Ammonium phosphate-based treatment: an innovative mineral-inorganic approach for the consolidation of mural paintings. Pilot tests and scientific investigation 36

Livia Bucşa, Mihai Barhală, Monica Mironescu, Iasmina Moza: Problems of restoring mural painting with advanced fungic decay 37

Giancarlo Ranalli, Gabriele Alfano, Giuseppe Lustrato: Middle and long-term microbial monitoring of bio-cleaned wall paintings at Monumental Cemetery of Pisa 38

Robyn E. Hodgkins, Alexander K. Tucker-Schwartz, Cecily M. Grzywacz, Robin L. Garrell: Determining acetic and formic acid vapor concentrations in museum environments by an improved ion chromatographic method with revised acid diffusion coefficients 39

Advancing Analytical Technologies 40

M.Ferretti, S.Legnaioli, G.Lorenzetti, A. Foresta, L.Pardini and V.Palleschi: On the joint use of portable X-Ray Fluorescence and Laser-Induced Breakdown Spectroscopy in Archaeometallurgy 41

R. Olmi, M. Bacci, C. Cucci, M. Picollo, S. Pieri, S. Priori: An innovative technique for investigating the degradation of plastic artefacts 42

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A. Andreotti, A. Cecchi, G. Cecchi, M.P. Colombini, C. Cucci, O. Cuzman, C. Fornacelli, M. Galeotti, F. Gambineri, I. Gomoiu, D. Lognoli, D. Mohanu, L. Palombi, S. Penoni, M. Picollo, D. Pinna, V. Raimondi, P. Tiano, C. Todaro, G.Valentini: Effects of low-fluence laser irradiation on mural paintings: test studies on a fresco and a secco model samples 44

B. Brunetti, E. Catelli, R. Mazzeo, C. Miliani, S. Prati, F. Rosi, G. Sciutto, A. Sgamellotti: Development of new systems for the preparation of paint cross sections 45

POSTERS 46

I. S. Artemieva, K. B. Kalinina, I. Bonaduce, M. P. Colombini, V. A. Korobov: Technological Examination of Composition of Transferred Grounds of Italian Paintings (XV-XVI centuries) from The State Hermitage Museum Collection 47

A. Gambirasi, E. Cattaruzza, M. Favaro, P. Guerriero, L. Peruzzo, P. A. Vigato: The characterization of ancient materials: new perspectives offered by Electron Backscatter Diffraction (EBSD) 48

M. J. Guttmann, V. Pitthard, M. Griesser, Olimpia Coman-Sipeanu: Binding media analysis of some Romanian glass icons 50

J.J. Łucejko, F. Modugno, E. Ribechini, M.P. Colombini: Wood tar and wood resinous extracts as ingredients of Egyptian embalming materials: a GC/MS study 51

A. V. Terlixi, I. Bonaduce, M. P. Colombini, A. Lluveras, E. Ioakimoglou, J. Perdikari, A. Karabotsos: Multi - method approach of an overpainted post Byzantine icon belonging to the Byzantine Christian Museum of Greece 53

A. Tognazzi, G. Leone, A. Magnani, M. Aggravi, A. M. Dattilo, L. Bracchini, C. Rossi: A new tool for the assessment of ancient ceramic production technologies. ToF-SIMS investigation of the ceramic impasto in fragments from the archaeological site of Quartaia (Italy) 55

S. Wei, V. Pintus, M. Schreiner: Characterization of Polymers Used in Artworks by Pyrolysis Chromatography and Mass Spectrometry 57

P. Baraldi, F. Paolucci, A. Rossi: Identification of a survived polychromy of the Apollo statue in Villa Corsini (Florence) 58

A. Kriznar, M.V. Muñoz, F. de la Paz, M. A. Respaldiza, M. Vega: Non-destructive analysis of polychromed terracotta sculptures from the 15th and 16th centuries by portable XRF 60

S.Legnaioli, A. Gioli, R.V. Iungo, G.Lorenzetti, P. Nieri, L.Pardini, V.Palleschi: Multispectral Imaging and Colorimetric Analysis of the ‘Adoration of the Child’, by the Master of the Castello Nativity 62

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L. Marras, A. Pelagotti, E. Massa: An integrated approach to painting diagnostics: the case-study of two Vasari panels 63

Y. Keheyan: Characterization of Ararat cochineal 64

S. Cagno, S. Bugani, G. Nuyts, K. de Vis, J. Caen, L. Helfen, M. Cotte, K. Janssens: The browning of stained glass windows: characterization of Mn-rich bodies and evaluation of cleaning methods 65

A. Andreotti, M.P. Colombini, A. Lluveras, F. Piqué, G. Torraca: Beeswax and saccharides in Roman wall paintings at Herculaneum: original materials? 66

   

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UNDERSTANDING MATERIAL DEGRADATION

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Photophysics of ancient anthraquinone-Al complexes: from the laboratory to the artwork

Aldo Romani1,2, Catia Clementi2, Chiara Grazia1, Costanza Miliani3

1Department of Chemistry, University of Perugia, via Elce di Sotto 8, 06123 Perugia Italy 2SMAArt, c/o Department of Chemistry, University of Perugia, via Elce di Sotto 8, 06123 Perugia Italy 3CNR-ISTM, c/o Department of Chemistry, University of Perugia, via Elce di Sotto 8, 06123 Perugia Italy

Since the antiquity, anthraquinone derivatives, naturally obtained from plants and insects, have been

used for dyeing textiles and/or to produce insoluble organic pigments suitable for different painting

techniques. In order to obtain these compounds, the early unconscious chemists mixed, for instance,

carminic acid from Polish cochineal (Porphyrophora polonica L.) or alizarin and purpurin from Rubia

Tinctorum L. roots, with potash alum (Al2(SO4)3K2SO4·12H2O) producing organo-metallic complexes called

lakes.

O

O

O

OH

O

OO

HO

Al

In the last fifteen years non-destructive spectroscopic techniques have become basic elements in the

cultural heritage diagnostics and conservation. Among these, UV-Visible spectroscopy, both in absorption

and emission, is actually the most suitable tool in order to obtain information concerning organic dyes and

pigments present in artworks.1,2 For this reason, investigation of the lake’s photophysics properties in

solution, in the micro-crystalline solid phase and in painting mock-ups become absolutely necessary in order

to rationalize and understand the experimental data collected from a real artwork. In this study, alizarin and

purpurin aluminium lakes have been produced in solution following the complexation reaction by both

spectrophotometric and fluorimetric measurements. Stoichiometry, fluorescence quantum yield and

fluorescence lifetime of the complexes have been determined. As a complementary approach, the same

lakes have been produced following ancient recipes and then characterized in the solid phase and then in

solution using steady-state and time-resolved spectroscopies comparing their properties with those

previously obtained. The satisfactory agreement confirm how the basic study in the “relatively simple”

environment, the solution, is fundamental in order to fully understand the properties of “more complex”

systems such as the solid state or the painting layer.

References

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C. Miliani, A. Romani and G. Favaro, “Acidichromic Effects in 1,2- and 1,2,4-Hydroxyanthraquinones. A spectrophotometric and Fluorimetric Study” J. Phys. Org. Chem., 2000, 13, 141-150. C. Clementi, B. Doherty, P. L. Gentili, C. Miliani, A. Romani, B.G. Brunetti, A. Sgamellotti, “Vibrational and electronic properties of painting lakes”, Applied Physics A, 2008, 92(1), 25-33    

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Comparison of Single Shot and Double Shot Technique of Py-GC/MSfor ageing studies of modern paint materials

Valentina Pintus1,2, Shuya Wei1, Manfred Schreiner1,2

1 Institute of Science and Technology in Art, Academy of Fine Arts, Schillerplatz 3, A-1010 Vienna, Austria 2 Institute of Chemical Technologies and Analytics, Analytical Chemistry Division, Vienna University of Technology, Getreidemarkt 9/161, A/1060 Vienna, Austria v.pintus@akbild.ac.at; s.wei@akbild.ac.at; m.schreiner@akbild.ac.at

In order to understand fast photo-oxidative deterioration of synthetic binding media in modern and

contemporary art and to investigate their chemical behavior exposed to UV light, ageing studies on these

materials were carried out. Pure synthetic materials such as PLEXTOL D498, PRIMAL AC33 and ROHAGIT

SD15 but also mixed with different inorganic pigments (titanium white rutile and anatase, cadmium red,

cadmium yellow, hydrated chrome oxide, ultramarine blue dark, raw umber cyprus and ivory black) were

identified and analyzed before and after UV exposure for different periods by means of Pyrolysis-Gas

Chromatography/Mass Spectrometry (Py-GCMS), with particular attention to the comparison of the Single

Shot and Double Shot modes. Additionally, these analyses have been complemented by Fourier transform

infrared spectroscopy-attenuated total reflectance (FTIR-ATR).

The Single Shot mode based on the pyrolysis for the analysis of polymers and the Double Shot

mode perform two analytical techniques on a single sample: 1) thermal desorption program for the analysis

of the volatile compounds such as additives, monomers, oligomers etc. During measurement the cup

containing the sample, which is mounted in the auto sampler, is dropped down into the furnace with the

desired temperature conditions (around 300°C). When the thermal desorption is completed (approximately

16 minutes) the cup is pulled up again to the stand by position at room temperature and GC/MS analysis

starts. 2) As soon as the GC/MS analysis of the volatile compounds is completed the cup is pulled down

again into the furnace in order to perform the Py-GC/MS of the polymers themselves. Double Shot technique

is hardly used for the analysis of art materials and only a few scientific investigations in others research field

have been carried out and described in the literature [1,2].

By comparing UV-aged and non-aged samples clear variations as well as the formation of new

peaks/products could be determined. Especially more pronounced differences were observed when the

synthetic materials are in combination with pigments, i.e. paints. The main difference between the results

obtained by Py-GC/MS for the UV-aged and unaged sample in the case of PLEXTOL D498 is the total

decrease of the phenolic antioxidant, which was possible to detect just by the Double Shot mode. Another

peak, which was hardly detectably particularly when Plextol D498 was mixed with blue ultramarine pigment,

was related to the butyl group.

Although the temperature conditions are quite unstable due to its high sensitivity, the Double Shot

method allows the characterization of the volatile compounds in a more precise and specific way than with

just the Single Shot technique.

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References

[1] Herrera M., Matuschek G., Kettrup A., 2003. Fast identification of polymer additives by pyrolysis-gas chromatography/mass spectrometry. Journal of Analytical and Applied Pyrolysis, 70: p. 35-42.

[2] Lee J. G., Lee C.G., Kwag J. J., Buglass A. J., Lee G. H., 2005. Determination of optimum conditions for the analysis of volatile components in pine needles by double-shot pyrolysis–gas chromatography–mass spectrometry. Journal of Chromatography A, 1089: p. 227-234.

   

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Degradation of Emerald green in Descente des vaches (1834-35) by Theodore Rousseau: an analytical study

Katrien Keune

Private Paintings Research Scientist, Kortenaerstraat 82, 2315 TP Leiden, The Netherlands katrien.keune@gmail.com

Emerald green (copper acetoarsenite, Cu(C2H3O2)2·3Cu(AsO2)2) was a popular stable brilliant green

pigment in the nineteenth century. The pigment was found in Theodore Rousseau’s Descente des vaches

(1834-35), an oil painting that is currently in poor condition. Darkening, various cracks and surface

deformations affect the appearance of this painting. Descente des vaches was one of the subjects of an

extended (analytical) study into the darkening and transparency of 19th Century paintings. Many paint

samples taken from different areas from Descente des vaches were investigated with various analytical

techniques. In this paper the analytical study of degraded Emerald green pigment in oil paint is presented

and a hypothesis of the degradation mechanism of Emerald green is proposed.

Raman spectroscopy confirms the presence of Emerald green and the absence of other types of

copper arsenate pigments in the paint cross-sections. In one of the paint cross-sections, the Emerald green

particles look disintegrated in the backscatter electron image and they exhibit “halo” of organic-rich material.

Elemental mapping of this paint cross-section shows a significant spatial distribution of copper and arsenic.

Copper is found in and around the Emerald green-containing paint layer, while arsenic is found throughout

the whole multi-layered paint sample. Even in the varnish layer, arsenic is found. Imaging-FTIR detects

copper carboxylates with a similar spatial distribution as copper in the elemental map.

When Emerald green pigment was mixed with fatty acids in solution in the laboratory, the reactivity of

Emerald green was seen within weeks: the pigment had reacted to copper soap and arsenic trioxide

(arsenolite, cubic).

This supports the hypothesis that in a paint layer Emerald green reacts with fatty acids from the oil

resulting in copper soap and arsenic trioxide. The copper soaps seem not to diffuse in a large extent into the

paint system, while arsenic trioxide migrates all over the paint system. The influence of degraded Emerald

green and the redistribution of arsenic trioxide on the appearance and darkening of Descente des vaches is

not clear. The observation of migration of arsenic trioxide in relation to degraded Emerald green is not limited

to Rousseau’s Descente des vaches, but has been found in other works of art, as will be demonstrated in

this paper.

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What can proteomics do for cultural heritage?

Gabriella Leo1, Piero Pucci1, Gennaro Marino1, Leila Birolo1, Laura Cartechini2, Antonio Sgamellotti3, Ilaria Bonaduce4, Alessia Andreotti4, Maria Perla Colombini4.

1Dipartimento di Chimica Organica e Biochimica, Università di Napoli “Federico II”, Napoli, Italy. 2Istituto di Scienze e Tecnologie Molecolari, CNR, c/o Dipartimento di Chimica, Università degli Studi di Perugia, Perugia, Italy 3Dipartimento di Chimica, Università degli Studi di Perugia, Perugia, Italy 4Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Italy. birolo@unina.it

In the context of artistic and historic objects, the identification of proteins is still a challenging task,

because of the very low amount of sample available, because of the complex and quite variable chemical

composition of the paints, because of the possible simultaneous presence of several components, and

because of the degradation of the original materials as a result of aging and pollution. We proposed to adapt

proteomic strategies for the identification of proteins in binders of paintings, but also in seeds, food remains

in archaeological find, etc.., to overcome requirements and difficulties presented by specific samples. In

particular, tryptic hydrolysis in heterogeneous phase, followed by the analysis by LC-MS/MS, was

successfully used to unambiguously identify milk proteins in a sample from a painting decorating the vaults

of the upper church in the Basilica of St. Francis in Assisi (Leo et al., 2009).

Moreover, similar strategies were exploited for the characterization of the aging products of

proteinaceous materials in masterpieces, identifying deamidation as the major modification taking place.

Deamidation could be related to the treatments undergone by the binders in the realisation of the work of art,

as well as the aging of artistic and historic objects (Leo et al., in preparation). The systematic analysis of

samples from the 14th century frescoes of the Monumental Cemetery in Pisa indicated extensive

deamidation occurring on most of the peptides identified, suggesting that the miniature molecular clock, as

Robinson and Robinson defined any amide residue present in peptides or proteins (Robinson et al., 2004),

might well be used as molecular marker in artworks.

References

Robinson, N. E.; Robinson, A. B. (2004) Molecular Clocks: Deamidation of Asparaginyl and Glutaminyl

Residues in Peptides and Proteins. Althouse Press.

Leo G, Cartechini L, Pucci P, Sgamellotti A, Marino G, Birolo L. (2009) Proteomic strategies for the

identification of proteinaceous binders in paintings. Anal Bioanal Chem. 395, 2269-80.

 

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Study on binding media in oil paintings: characterisation of linseed oil by DEMS, TGA and GC-MS

I. Bonaduce1, L. Carlyle,4 M. P.Colombini1, C. Duce1, C. Ferrari3, R. Mazzeo2, S. Prati2, E. Ribechini1, P.

Selleri1,2, M.R. Tiné1, E. Tombari3, J. H.Townsend.5

1Dipartimento di Chimica e Chimica Ind., via Risorgimento 35, Università di Pisa, 2Microchemistry and Microscopy Art Diagnostic Laboratory, via Guaccimanni 42, 48100 Ravenna, Università di Bologna 3 Istituto per i Processi Chimico-Fisici del CNR, via G. Moruzzi 1, 56124 Pisa, Italy 4 Departamento de Conservação e Restauro, FCT/UNL, Campus de Caparica, 2829-516 Caparica, Portugal 5 Conservation Dept, Tate, Millbank. London SW1P 4RG, UK celia@dcci.unipi.it

A study on lipid binding media, and more specifically linseed oil, is presented. Oil pre-treatments

were commonly used by artists to obtain binders with modified properties, such as different handling qualities

or colour. This study focuses on the role of the oil processing methods, such as heating, addition of lead-

based dryers or water washing, and how these factors can influence the ageing of linseed oil paints.

The study was performed using linseed oils and paint reconstructions prepared as part of the de

Mayerne HART project (Historically Accurate Reconstruction Techniques), according to an accurate

historical description of the painting techniques of the 19th century. Oils were mechanically extracted from

linseeds and then processed by different methods, based on the use of water washes, different heating

treatments and the addition of driers. Paint layers were then prepared using Lead White or Vine Black as

pigments.

Multiple techniques were use to investigate the drying, polymerization and oxidative degradation of

the linseed oil paints, including thermogravimetry analysis (TGA), gas-chromatography mass-spectrometry

(GC-MS), direct exposure mass spectrometry (DEMS) and Fourier Transform Infrared Spectroscopy (FTIR).

GC-MS was used to characterise the non-polymeric chemical fraction of the oils and paint

reconstructions, and thus to help understand the oxidative degradation undergone by the materials during

ageing. It was possible to evaluate how ratios of palmitic to stearic acid (normally used to identify the drying

oil), and azelaic to palmitic acid (normally used to indicate a drying oil) were affected by the oil treatments

and the different pigments.

DEMS enabled the different molecular weight fractions of the samples to be simultaneously

characterised, and thus helped highlight the cross-linking, oxidation, hydrolysis and carboxylate formation

that occurs during ageing, and how this is affected by the addition of a pigment.

TGA revealed changes in the molecular weight of the oils during ageing and the formation of higher

molecular weight fractions, which were subsequently characterised by FTIR. TGA proved to be an excellent

tool to compare the oils and paint reconstructions, highlighting the different physical behaviour of oils that

were processed using different methods.

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The combination of thermal analysis with molecular techniques such as GC-MS, DEMS and FTIR

enabled a model to be developed, for helping understand how oil pre-treatments produce binders with

different physico-chemical qualities, and how this can influence the ageing of an oil paint film.

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Characterization of efflorescence on 20th Century oil paintings – an analytical study

Aviva Burnstock2, Klaas Jan van den Berg1, Suzan de Groot1, Laura Hinde2

1ICN – Instituut Collectie Nederland, Onderzoek, Hobbemastraat 22, PO box 76709, 1070 AA Amsterdam, The Netherlands 2Courtauld Institute of Art, Department of Conservation and Technology, Somerset House, London WC2R 0RN, UK aviva.burnstock@courtauld.ac.uk, klaas.jan.vd.berg@icn.nl

Whitening of the surface of paintings is a common phenomena reported by conservators of modern

paintings. Light scattering can be caused by the accumulation of surface material from the environment,

migration of materials from the painting or degradation products. Analysis of surface material from paintings

that exhibit surface whitening has included fatty acids, metal soaps and salts.

This paper examines superficial whitening of the paint surface in selected 20th century paintings. Two

classes of whitening were characterised: 1) Efflorescence caused by free fatty acids from paintings in oil

media and 2) localised deposits of salts that derive from migration of components and degradation products

from inorganic painting materials.

Light-scattering crystal-like entities were characterised in samples from paintings by Serge Poliakoff

(d.1956), Antoni Tapies ( d.1964), and Victor Vasarely (1949-1953), visible using light and SEM microscopy

and elemental analysis. Organic analysis of the surface material identified saturated free palmitic and stearic

acids (FFAs) that may derive from the oil binding medium (from hydrolysis after the paint formulation and

drying or already naturally present FFAs) or from free fatty acids added by manufacturers to facilitate

dispersion of the pigments into the medium. The absence of reactive metal ions (in the ground and paint)

from these works, and the correspondence of the densest surface whitening on medium rich paints suggests

that fatty acids migrate to the surface most readily where there is a “reservoir” of medium. Stratigraphic study

of the paintings suggested that the source of the FFAs was not limited to the surface paint but could derive

from a medium rich underlayer. The paint thickness, and the presence of hydrogenated castor oil in the

medium also affected the density of FFA-type whitening on the surface.

White material deposited on the surface of a painting in mixed media comprising elements of

newsprint by Tàpies was identified as sodium sulphate. SEM images illustrated a broken surface

characteristic of the effects of salt migration. It is postulated that soluble sulphuric acid in the newspaper

reacted with sodium ions to form sodium sulphate. Sources of sodium could include the paper, which may

contain sodium hydroxide as a remnant of production processes, sodium carboxy-methyl cellulose adhesive,

or additives to the alkyd paint, such as sodium stearate. Water-soluble sodium compounds that are

mobilised in cyclical changes in RH and this may influence the deposition of the white salts on the surface of

the painting. The density of the salt deposit was limited to areas of alkyd emulsion containing paint and thus

the media significantly influences the whitening due to salt migration.

Potassium sulphate salts were identified in localised regions of the painting by Vaserely, painted using

linseed and rapeseed oil media. A network of fungal hyphae in underlayers of paint, and the use of an

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absorbent zinc oxide containing ground combined with historical environmental data for display suggest

favourable conditions for salt formation and migration. The localisation of salt formation and whitening was

related to local use of pigments and the thickness of the overlying paint layers.

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Evaluation of accelerated aged studies on cultural heritage objects organic in origin, in particular parchment and artists' varnishes

Marianne Odlyha1, Laurent.Bozec2, Réne Larsen3,Terje Grontoft4

1Thermal Methods and Conservation Science, Birkbeck College, Malet St, University of London WC1E 7HX 2 Eastman Dental Institute ,UCL, 256 Gray’s Inn Rd.,London UK WC1X 8LD and London Centre for Nanotechnology, 17-19 Gordon St.London,UK WC1H OAH 3 School of Conservation, Esplanaden 34, Copenhagen, Denmark 4Norwegian Institute for Air Research (NILU) , Norway m.odlyha@bbk.ac.uk

Recent work in two EC projects IDAP “Improved Damage Assessment of Parchment”and

PROPAINT “Improved protection of Paintings during Exhibition, Storage and Transit” has involved

accelerated ageing experiments and the use of pollutants both inorganic (NO2,O3,SO2)and organic (volatile

organic acids) in the presence and absence of light and conditions of elevated RH. In this paper results of

analyses will be presented which focus on the use of thermal, spectroscopic, high resolution surface

analytical techniques (XPS,SIMS) and scanning probe microscopy to study the effects of accelerated ageing

on organic cultural heritage materials, in particular parchment and varnishes used on paintings. The

outcome of the ageing experiments will be reported and the conditions used will be considered in the light of

naturally aged materials. Attention will also be directed to the source and preparation of samples, for

accelerated ageing and in the case of varnishes the nature of the substrate used. In the case of parchment,

damage assessment has been made using atomic force microscopy (AFM) . Quantification of the resulting

images gives a value for the extent of surface coverage containing intact D-banding of its collagen structure

and is used as a marker for extent of damage, together with shrinkage temperature and response of

mechanical properties to programmed changes in RH. In the case of varnish glass transition temperature

measurements have been made using dynamic mechanical and micro-thermal analysis and their used to

evaluate extent of change, together with surface analytical techniques.

21  

CHARACTERISING, INTERPRETING AND UNDERSTANDING HERITAGE

MATERIALS AND OBJECTS

22  

Analytical study of ancient pharmaceutical preparations

M.P. Colombini, I. Degano, F. Modugno, E. Ribechini, M. Rocchi Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Via Risorgimento 35 - 56126 Pisa, frances@dcci.unipi.it The identification of the substances and the processes used in the past for formulating of medical,

cosmetic and pharmaceutical preparations is of great interest in the context of archaeometric researches

aimed to reconstruct the evolution of science, technology and knowledge in the course of the centuries, and

to trace the role and the uses of various materials in past societies.

The presented results are relative to the chemical analysis of organic natural substances in samples

collected from vessels belonging to historical collections of pharmaceutical preparations (17th-19th): the

Aboca museum of Sansepolcro (Arezzo, Italy), the Real Cartuja de Valldemossa (Palma, Majorca, Spain)

and the Museum of S. Agostino (Palazzo Tursi, Genova, Italy).

This research was part of the national project Prin07: Colors and balms in antiquity: from the chemical

study to the knowledge of technologies in cosmetics, painting and medicine (Cofin2007).

Analyses have been performed by gas chromatography-mass spectrometry (GC/MS), aimed at

separating and identifying significant molecular markers to be used to assess the composition of the

materials. The research focused on lipid and terpenic compounds, which are the main components in the

majority of the ancient pharmaceutical preparations investigated. The presence of fatty acids, diacids,

hydroxy-acids, long chain alcohols and specific alkane patterns highlighted the presence of beeswax, animal

fats, plant oils and pine resin. The results have been interpreted contextually with information obtained from

the historical documents and ancient pharmaceutical treatises, in order to reconstruct the original recipes of

the formulations.

23  

An analytical survey on formulations of 20th Century oil paints

Francesca Caterina Izzo*1,2, Klaas Jan Van Den Berg*1, Henk Van Keulen1, Rossano Piazza2, Guido Biscontin2

1ICN – Instituut Collectie Nederland, Onderzoek, Hobbemastraat 22, 1070 Amsterdam, The Netherlands 2University Ca’ Foscari of Venice, Department of Environmental Sciences, Via Torino 155/b, Venezia Mestre, Italy fra.izzo@unive.it, klaas.jan.vd.berg@icn.nl

From the 19th Century, artists’ oil paints were increasingly produced on an industrial scale and include

a number of additives, e.g. stabilisers, dispersion agents and driers. These additives allowed for faster

production, stability, prolonged shelf life and uniform handling properties of the paints in and from the tubes.

Sometimes, resins, fillers and adulterants were added to produce less expensive paints.

The identification of binding media and additives in paint samples is important for understanding

painting techniques and to understand degradation phenomena such as efflorescence, water sensitivity and

so-called ‘weeping paints’. This knowledge may also play a role in the design of preventive conservation

practice.

The aim of this research was to identify oil binders and find evidence for the use of lipid and other

organic additives in 20th century manufactured oil paints.

Several oil paint manufacturers were contacted and interviewed to obtain more information about

modern formulations of oil paints. Samples from oil tubes by Winsor&Newton, Talens, Old Holland, Maimeri,

Gimborn,etc, dating from 1920 to 1990 as well as samples from a number of modern oil paintings were

investigated.

Analytical methods such as Optical Microscopy, Scanning Electron Microscopy with electron

microprobe (SEM/EDS), X-Ray Fluorescence Spectrophotometry and Fourier-Transform Infrared

Spectrophotometry (FT-IR) were used in combination with Gas Chromatography–Mass Spectrometry (GC-

MS). For GCMS, a novel analytical methodology for modern and contemporary oil paints using was

developed and applied, consisting of a simplified extraction procedure adapted from a method used by the

Doerner Institute. The derivatives were analyzed using Gas Chromatography-Mass Spectrometry (GC-MS).

The data were treated by several multivariate chemometric techniques, such as cluster analysis and principal

component analysis (PCA), in order to compare and classify oil paints on the basis of binders and additives

present in their formulations.

The results obtained from GC-MS analysis on contemporary oil paints are consistent and reproducible

and the analytical methodology is able to determine and quantify low percentages of stearates in modern oil

paintings. As a prime example, Untitled 1964/’65 by Jasper Johns (Stedelijk Museum Amsterdam) is

presented – a work in which it is known for a fact that stearates are present in the paints but could not be

detected previously.

24  

Developments in the technique of early oil painting in Germany (c. 1330-1530)

Ursula Baumer, Patrick Dietemann, Irene Fiedler, Jeanine Walcher Doerner Institut, Barerstr. 29, 80799 Munich, Germany baumer@doernerinstitut.de

At the beginning of the 16th century, the technique of painting in oil was well developed and applied

all over Europe. The drying and ageing properties of oils in admixture with pigments were well understood

and mastered leading to the creation of impressive works of art. Binding media analyses of various German

painters of that time were performed in our institute, including paintings by Albrecht Dürer (1471-1528), Hans

Holbein the Elder (1465-1524) and Albrecht Altdorfer (1480-1538) or painters from the Hamburg painting

school such as Absolon Stumme († 1510) or Hinrik Bornemann (1450-1499). In most of the investigated

panel paintings the traditional drying oils were modified by boiling and the addition of drying agents. It must

be emphasised that often significant additions of proteinaceous binders, mostly egg, but also animal glue or

even blood albumin, were also found.

However, the origins of the oil painting technique are still somewhat unclear. Although it is well

known and established that drying oils were used in Northern Europe painting long before the 15th century,

there were undoubtedly eminent developments in Flanders at the beginning of the century. At the same time,

German painters working in Cologne were known for their perfect and elaborated style and painting

technique in oil (‘Altkölner Malerei’, Cologne School). Famous masters, such as the Master of the Saint

Veronika and Stefan Lochner († 1451) belong to this school, which can be traced back to the beginning of

the 14th century.

Today approximately 600 paintings of the Cologne school are preserved worldwide, whereas, the

two biggest collections are housed in the Wallraf-Richartz-Museum & Fondation Corboud, Cologne, (around

300 panels) and Bayerische Staatsgemäldesammlungen, Munich (around 150 panels). In a collaboration

involving these two institutions, 53 of these paintings are studied by an interdisciplinary team of

conservators, scientists and art historians in a three year project funded by the Federal Ministry of Education

and Research (BMBF). The study includes art technological investigations with non-destructive techniques

such as microscopy, X-Ray, IRR, UV-photography, and X-ray-fluorescence analysis, as well as analyses of

pigments and binders by SEM/EDX, GC/MS, and amino acid analysis.

The talk will focus on the comparison of the materials and painting technique of the Cologne School

oil paintings from 1330 – 1450 with later German paintings from the early 16th century. A special emphasis

will be placed on the types of drying oils used, the processing of the oils such as thermal treatments or

addition of siccatives, as well as the occurrence of proteinaceous media.

25  

A data mining analysis over a database of materials of Portuguese painting from the 15th and 16th centuries

Vanessa Henriques Antunes, Orlando Anunciação

Instituto História da Arte da Faculdade de Letras de Lisboa, Laboratório de Conservação e Restauro José de Figueiredo do Instituto dos Museus e da Conservação (LCRJF-IMC), INESC-ID, Instituto Superior Técnico, Lisboa, Portugal vanessahantunes@gmail.com

Abstract: Our paper integrates a project that has as its purpose to exploit the work that has been

initiated since 1970’s in LCRJF-IMC and consists in the study of ground layers on Portuguese wooden

painted panels of the 15th and 16th centuries, supported by the compilation and interpretation of the

laboratorial exams obtained through different sensitive analytical techniques. In our paper we introduce the

procedures that led us to the creation of a specific database and how we intend to analyze data by applying

methods such as classification with decision trees to prove the existence of identities between Portuguese

painting "workshops".

Objectives of the Database: The main objective of this project is an integrated study of the painting

techniques, specifically addressing the methodology used for the preparation of the ground layers in the

various Portuguese "workshops" from the end of Gothic and Renaissance to Mannerism. There is no

systematic study in Portugal as the one proposed in this project, and the identification and contextualization

of the ground layer in the paintings of the period under study will bring a new perspective on Portuguese

painting. It will explore the relationships between the artists, their criteria and material resources used on the

creation of their works. Those aspects will provide a vital contribution to prove the existence of identities

between "workshops", a key issue for the scientific community dedicated to the study of this matter.

Data analysis: Another important contribution will be the data mining analysis that is going to be

performed over our database. Data mining techniques, such as decision tree learning, have the ability to

discover patterns in the data that explain the observed differences. A model is induced from the data to

explain the variable in study. Decision trees produce interpretable models that can be validated with domain

knowledge. An example of an analysis that can be performed is to build a decision tree model that uses

information about stratigraphies to discriminate between “workshops”. This kind of analysis has the potential

of giving new insights about the differences in the techniques used to produce the paintings.

Conclusions: The expectable results of Data mining techniques will allow the ground materials

characterization of paint collections from different national and regional Museums .The nature of this

contribution will identify material and production techniques that benefit the understanding of Portuguese

painting. It will benefit particularly the regions where paintings are exhibited: Lisbon, Évora, Coimbra or

Viseu. Some of those regions have a problem of scientific and technological development and this

investigation theme will contribute to the improvement of future investigations on their patrimony

conservation issues.

26  

The online dissemination and public presentation of this database and its data mining analysis

results will represent an evolution forward towards the preservation of Portuguese paintings and safekeeping

for future generations. It will enable an integrative knowledge to the dissemination of conservation

recommendations concerning the artistic studies, investigation and Cultural Heritage protection, with future

educational and scientific contributions at an international level.

27  

Technical study of varnishes from the collection of antique furniture belonging to the Prince of Liechtenstein

Václav Pitthard 1, Susanne Käfer 2, Silvia Miklin-Kniefacz 3, Marta Anghelone 1, Martina Griesser 1, Sabine

Stanek 1 1 Conservation Science Department, Kunsthistorisches Museum, Burgring 5, Vienna, A-1010, Austria 2 Restoration and Conservation of Furniture and Wooden Objects, Eyzinggasse 23, Vienna, A-1110, Austria 3 Atelier for conservation and restoration (metals, urushi), Bernardgasse 4/1, Vienna, A-1070, Austria vaclav.pitthard@khm.at

During the current extensive renovation of the 17th century residence of the Princely family of

Liechtenstein in Vienna, exquisite antique furniture from the City Palace has been under restoration

treatment. One of the aims of the restoration was the study of the coating techniques applied and for some

selected objects also the reconstruction of the original coatings still partly preserved. To fully understand the

composition of the coatings and varnishes microscopic investigations of cross-sections using light and

electron microscopy (SEM) and simultaneous analyses of binding media by gas chromatography-mass

spectrometry (GC-MS) were performed.

The paper shows selected results of this comprehensive project, which includes several exceptional

pieces of European and Asian furniture. In particular, four 19th century gilded upholstered chairs executed by

Carl Leistler, one 18th century di pietre dure table produced in the workshops of Giovanni Guliani and the

Castruccis, two 17th century Japanese Maki-e lacquer cabinets, and three 19th century chests with

incorporated Chinese lacquer panels, are presented.

The analysis of binding media of the coatings from the upholstered chairs showed an animal glue

based ground layer followed by an oil-resinous coating – composed of pre-polymerised linseed oil, Manila

copal, pine resin, and Venice turpentine. Manila copal, firstly used in Europe in the middle of the 19th century,

indicates that contemporary materials of the period were applied.

In the case of the 18th century table, during the initial documentation, an original dark green polychrome layer

– a so-called “bronzing” – was observed under the current gilding, which was examined with regard to its

stratigraphy, pigments, and binding media.

Investigations carried out on the two richly decorated lacquer cabinets clarified the multilayer

stratigraphy of the coating based on several layers of a black Asian lacquer and transparent varnishes of

European origin. Due to the topmost varnishes, today the appearance of these furniture pieces resembles

European lacquer cabinets and their Japanese origin was, therefore, doubted. By Pyrolysis-GC-MS urushiol

was detected in the black lacquer layers clearly proving the Japanese origin of these lower layers and,

therefore, also the wooden furniture.

Concerning the three chests, which are said to be manufactured in Vienna during the 19th century,

certain doubts about their origin came up as the front doors seem to be Chinese lacquer panels. The study

revealed that the furniture incorporates Chinese lacquer panels within frames for the doors, whereas the

body of the chests itself is veneered and coloured.

28  

29  

Authentication of wall paintings made by the Older Villach’s Workshop on bases of material and technique analysis

Anabelle Križnar

Department of Art History, Faculty of Philosophy, University of Ljubljana, Slovenia

The so called “Older Villach’s Workshop” was an important painting circle in Carinthia of the first half

of the 15th Century, in which mostly wall paintings have been carried out. This workshop was founded by

Friedrich of Villach (Friderik von Villach, Friderik Beljaški) and was based in the town of Villach in the

southern part of what is today Austria. Several wall paintings have been attributed to it on the bases of art-

historian interpretation, however some of them were generating several doubts. That is why an

interdisciplinary project has been dedicated to it, in order to find more about the materials and painting

techniques applied by Friedrich and its workshop, which would allowed us to distinguish between the

genuine works and those made by Friedrich’s followers. There were no previous studies carried out in

Austria and also very few information can be found in state archives. The selected churches were those in

Mariapfarr (1420–25), Millstatt (signed and dated in 1428), St. Gandolf an der Glan (1435–40),

Deutschgriffen (chor after 1452, nave around 1455), Unterferlach (1420–25) and Feistritz an der Drau

(around 1440). The later two were considered that could have been painted by different masters.

All cycles were first precisely studied in situ in order to see the painting procedure – the use of

incisions, predrawings, underpaintings, the way of colour modelling, as well as the application of mortars,

their division in giornatte and possible use of lime-wash. Second, small samples of mortars and pigments

were extracted from previously selected areas. These samples were grounded or prepared as cross-sections

and further on studied by different laboratory procedures and instrumental techniques: optical microscopy,

SEM-EDS, FTIR and XRD.

The results of these analyses showed important similarities, but also differences between the above

mentioned wall paintings. These can be observed already in the composition of mortars. The “Older Villach’s

Workshop’s” mortars are made of lower quantity of lime and more sand. Similar mortar, but with more lime

was found in Feistritz an der Drau, while in Unterferlach a high quality mortar of lime and crushed marble or

lime-rock was found. While in Friedrich’s works and in Unterferlach the lime-wash was applied seldom and

locally in very thin layers, in Feistritz there were larger areas covered with thick lime layer. At the same

location also strong incisions have been used, which is not the case for other studied works. The pigments

applied are mostly the same, lime white, yellow and red ochre’s, green earth or malachite, azurite and

umbra. The best painting technique was carried out in Unterferlach, where mostly all of it was painted a

fresco. In the works of Older Villach’s Workshop a larger part was finished a secco, however on a good a

fresco base. In Feistritz mostly predrawings and underpaintings were painted on a fresh mortar, while the

rest in lime technique or a secco. These differences confirmed, that two different masters, who were,

however, very close to Friedrich´s work, painted Feistritz and Unterferlach.

30  

The Invisible Story of Esther: Unveiling an extraordinary collaboration between Sandro Botticelli and Filippino

Lippi in two 15th Century Cassoni. Comparative technical study of new findings with InGaAs IR Reflectography

Tomas Markevicius

European and American Paintings, National Gallery of Canada, Ottawa tmarkevicius@gmail.com

Around 1475 one of the most significant Early Renaissance nuptial chamber cycles, depicting the

Story of Esther was executed by Sandro Botticelli with the help of young Filippino Lippi. The six panels, now

distributed between Canada, France and Italy, originally decorated a pair of now dismembered cassoni or

marriage chests. The creation of the later 15th century cassone was obviously a collaborative process,

involving structural carpentry, carved and running moulding, pastiglia and punched gilding, as well as

decorative paintwork and actual, inset or in-situ paintings. While in such extended collaborations the attempt

to distinguish the contributions in terms of program and execution is very difficult, in the 15th century the final

credit was given to the major master, assuming the work of assistants as an integral part of the modus

operandi.

Art history however, has not been content with that logical convenience, and the authorship of the

cycle has been the subject of hot debate since the late 19th century, and continues today. Evidence from

technical examination, was not explored systematically in the past and therefore was not considered in the

attribution debate. In 2009 a comprehensive study was undertaken by the National Gallery of Canada: the

initiative in course joined enthusiastically by Le Centre de Recherché e des Restauration des Musées de

France in Paris, Canadian Conservation Institute in Ottawa and those with responsibility for the elements of

the cycle: Palazzo Pallavicini in Rome; Museé du Louvre, Museé Condé in Chantilly, and Museo Horne in

Florence.

The new findings, obtained with IRR reflectography using the new Hamamatsu digital camera with

InGaAs sensor (1750 nm) were critical not only confirming the attribution of the Derelitta to Botticelli, but also

discovering that another disputed side panel – the Triumph of Mordecai (NGC) belongs entirely to the hand

of the master. These and other exiting findings obtained during the first comprehensive comparative

technical study of Botticelli and Filippino approaches to modus operandi shed new light on the long lasting

attribution debate, and on early Botticelli studio practices, and highlight the role of multidisciplinary studies in

technical art history, introducing a further dimension also to the reunion of most elements of the cycle for the

first in more than 200 years, at Virtù d’Amore: Nuptial Paintings in the 15th Century Florence exhibition at the

Galleria dell’Accademia in Florence in June-November 2010.

31  

Backscattered-electron images of paint cross-sections, an information source for tracing paint defects

Annelies van Loon1, Katrien Keune2

1 Royal Picture Gallery Mauritshuis,Postbus 536, 2501 CM The Hague, The Netherlands 2 Private Paintings Research Scientist, Kortenaerstraat 82, 2315 TP Leiden, The Netherlands vanloon.a@mauritshuis.nl; katrien.keune@gmail.com

SEM/EDX is an established and essential technique for the analysis of multi-layered paint systems in

cross-sections. However, we have the feeling that its use is often limited to elemental analysis with EDX,

whereas we believe that the information obtained from the backscatter mode is just as valuable and

complementary to EDX. The backscattered-electron (BSE) image reveals the compositional contrast within

the paint system. It highlights elements with high and low atomic weight, which is particularly helpful in the

investigation of paint cross-sections, because pigments usually contain high atomic weight elements, such

as lead, arsenic or mercury, that contrast sharply with the surrounding binding medium that is composed

mainly of low atomic weight elements, such as carbon and oxygen. In this way, the individual layers, pigment

particles and their distribution, and organic constituents can be visualized in paint cross-sections. Thus,

pigment identification is not only based on elemental analysis with EDX, but also on particle size and shape

as shown in the backscatter image.

Besides the composition of the paint sample, information about ageing and degradation phenomena

in paintings can be deduced from backscattered-electron images. Defects, like (partially) degraded pigment

particles, dislocated constituents and newly formed materials within the multi-layered paint, can be observed

in the backscatter electron image. These defects are mostly characterised by undefined pigments borders,

deposits between paint layers or around particles, unexpected shapes of particles or amorphous greyish

paint areas (see Fig. 1 and 2). Alteration, degradation and migration processes and mechanisms can be

constructed from paint characteristics, i.e. form, composition, position, orientation, ect..

This paper focuses on the reading of backscatter images of paint cross-sections as a source for

paint defects in traditional oil paintings.

32  

Fig. 1.Backscattered-electron image (BSE) showing the dissolution and saponification of lead white in the priming layer. The fine lead white particles appear to have reacted away forming large transparent regions throughout the layer leaving only the largest particles intact. This corresponds to the observation of large lead white particles in a transparent brownish matrix in these areas on the surface of the painting. The paint cross-section is taken from a dark line in the sky in the painting River Landscape by Aert van der Neer dating from the mid-1650s (Mauritshuis, The Hague, inv nr. 912). Fig. 2. Backscattered-electron image (BSE) of partially photo-degraded vermilion particles. Adifference in structure is visible between the red (lower part of the particle) and the black (upper part of the particle) areas. The paint cross-section is taken from an (17th century?) overpaint on the painting Portrait of a Lady by Peter Paul Rubens (c. 1625) (Mauritshuis, The Hague, inv. nr. 251).

33  

X-radiography, 3D point to point and laser scanning for reconstruction and Neutron Diffraction analysis of 1st century High status Roman bronzes excavated from 3

burials in Kent, England.

D. Goodburn-Brown1, E.G. Godfrey2, W. Kockelmann2, and A.M. Paradowska2

1AMTeC Co-op, The Historic Dockyard, Chatham, Kent, ME4 4TZ United Kingdom 2ISIS Neutron Facility, STFC Rutherford Appleton Laboratory, Harwell Campus, Oxfordshire, OX11 0QX, United Kingdom

This paper reports on some conservation recording and studies undertaken on a group of bronzes,

excavated in 2007 along a highway in Kent. The sets of burial goods were found in 3 separate graves, two

with very similar groupings of artefacts. Many are similar to bronzes found in Pompeii, N. Germany and other

find spots in England. The vessel types are generally attributed to workshops in Southern Italy. The Kent

find is from a period shortly after the Romans had arrived in England and burial practices at this time usually

combine both native Iron Age and Roman traditions. A 3D point to point recording device was used to plot

the positions of individual studs and straps, in hopes of being able to reconstruct and identify the item. Due

to the high quality of metalworking and the question of whether the vessels might have been made locally or

S. Italian imports, a series of non-destructive analyses were undertaken at the Rutherford Appleton

Laboratories. The facilities utilised consisted of Neutron diffraction via ROTAX and ENGIN-X, the latter

instrument allowed for larger items to be studied, and analyses were driven via pinpointing areas to be

analysed on a laser scanned 3-D model of the item. Textural studies were also undertaken on GEM and

ENGIN-X. The series of recording and analytical experiments were undertaken as part of the conservation

work in order to explore the potential for artefact recognition, materials identification, workshop practice and

taphonomic variables (eg. conditions of similar artefacts buried in a chalk pit versus a sandy clay

environment).

34  

Non-invasive investigation vs. micro-destructive analysis: the case of Mondrian’s Victory Boogie Woogie

C.Miliani1,2, K.J. van den Berg3, B.G.Brunetti1,2, Suzan de Groot3, M. Vagnini2, Matthijs de Keijzer3, Henk van

Keulen3, Luc Megens3, A.Sgamellotti1,2, M.R. van Bommel3.

1 CNR-ISTM, via Elce di Sotto 8, 06123 Perugia Italy 2SMAArt, University of Perugia, via Elce di Sotto 8, 06123 Perugia, Italy 3 Netherlands Institute for Cultural Heritage, P.O. Box 76709, 1070 KA Amsterdam, The Netherlands

In the last decade a lot of efforts have been devoted to the implementation of non-invasive

analytical tools that allow to yield significant information without sampling, and offer the opportunity to

punctually examine the entire artwork [1]. The multi-technique non-invasive approach of MOLAB was applied

for the study of the Victory Boogie Woogie (1942-1944) by Piet Mondrian , offering a thorough description on

the layering and mixing of the different inorganic pigments and addittives [2]. Afterwards, some small loose

samples that had fallen off of the tacking margins of the painting during the dismounting process of the box

frame, have been analyzed using an array of micro-destructive methods, namely GC-MS, HPLC, micro-

Raman, micro-FTIR, SEM-EDS and XRD. This two steps analytical study, applied on an apparently

straightforward work such as the Victory Boogie Woogie, has offered the opportunity to highlight strengths

and limitations of the non-invasive approach as will be discussed in this paper.

References

[1] Miliani C., Rosi F., B.G. Brunetti, A. Sgamellotti, In Situ Noninvasive Study of Artworks: The MOLAB Multitechnique Approach, Acc. Chem. Res., 2010, 43 (6), pp 728–738

[2] Miliani C., K. Kahrim, B.G. Brunetti, A. Sgamellotti, A. Aldrovandi, M.R. van Bommel, K.J. van den Berg, H. Janssen, MOLAB, a mobile facility suitable for non-invasive in-situ investigations of early and contemporary paintings: the case-study of Victory Boogie Woogie (1942-1944) by Piet Mondrian. ICOM Committee for Conservation 15th Triennial Meeting, New Delhi, 2008. pp 857-864.

Acknowledgements

The work has been partially funded by the national project PRIN 08 “Innovative materials and

methods for the conservation of modern art “and by the European project “CHARISMA” Cultural heritage

Advanced Research Infrastructures: Synergy for a Multidisciplinary Approach to Conservation/Restoration,

FP7 INFRASTRUCTURE n.228330.

35  

DEVELOPING METHODS FOR MATERIAL STABILIZATION,

MONITORING, AND REPAIR

36  

Ammonium phosphate-based treatment: an innovative mineral-inorganic approach for the consolidation of mural paintings. Pilot tests and scientific investigation

G. Botticelli1, D. Carson2, G. Chiari2, F. Fratini3, M. Matteini4

1 Private conservator-restorer of mural paintings, Florence, Italy 2 Getty Conservation Institute, Los Angeles, USA 3 CNR-Institute for the Conservation and Enhancement (Valorizzazione) of Cultural Heritage, Florence, Italy 4 Conservation scientist, Florence, Italy

mmatteini@inwind.it

Consolidation and protection of stone artifacts and mural paintings are often hard tasks due to the

presence of highly porous materials, soluble salts, frequent high humidity and, in some cases, exposure to

the outside environment (e.g. marble statues, painted facades).

This treatment is not reversible, but durability, compatibility with the substrate and retreatability have

priority over reversibility in such conditions. The mineral-inorganic approach offers advantages as

demonstrated by classical methods, such as the barium hydroxide and the silicic esters treatments. More

recently, important results have been obtained using ammonium oxalate as a passivating agent on

carbonatic materials. Highly acid resistant calcium oxalate is formed.

Following a similar approach, ammonium phosphates have been now proposed for the consolidation

of carbonatic materials (Int. J. of Architectural Heritage: M. Matteini, S. Rescic, F. Fratini, G. Botticelli -

“Ammonium phosphates as consolidating agents for carbonatic stone materials used in architecture and

cultural heritage: a preliminary research.”)

Relevant advantages for the use of phosphates are a higher solubility of the reactant, leading to a

higher concentration compared to both barium hydroxide and ammonium oxalate; non-toxicity of the active

principle; high compatibility of calcium phosphates with calcium carbonate substrata and evident

consolidating action.

An extensive investigation is being carried out evaluating treatment conditions on old painted

plasters by in situ measurements (water absorption capacity, color evaluation) and laboratory analyses

(XRD, SEM-EDS mapping showing the distribution of the calcium phosphate in sections).

The preliminary results will be presented.

37  

Problems of restoring mural painting with advanced fungic decay

Livia Bucşa1, Mihai Barhală2, Monica Mironescu1, Iasmina Moza1 1 University "Lucian Blaga" Sibiu, Sibiu, 550063 B-dul Victoriei nr.10, Romania, 2 SC Restauro SRL Bucuresti, Romania

Genuine fresco by the ingredients and technique of execution used constitutes one of the supports

that biological factors can hardly colonize. Literature of the domain reports biological attacks produced by

microorganisms only in special cases, occurring after an increase in moisture support, as a result of

infiltration, flood, excessive touring, etc., or after use of inappropriate materials in restoration.

The paper presents the problems of a powerful fungal attack, occurred with a church mural painting

in Romania.

The Orthodox Church of Jina, historical monument, in the geographical region of Transylvania, was

built between 1795-1796 and decorated with an inner fresco in 1801. It was restored between 1987-1989.

Within 20 years, most of the scenes, but mainly the vaults were colored with a dark layer, which obstructed

the images. For this reason , the local community required a new restoration intervention. The biological

expertise made to this end pointed to the existence of a massive fungal attack, of which three different

varieties of Penicillium were isolated. Occurrence causes of the decay were explained by the use of calcium

caseinate dispersion in the restoration process, high level of ascension humidity, lack of ventilation,

intermittent warming, condense, etc.

In the achievement of the restoration project of the painting was started a co-operation between the

biologist and the restorer, so as to find the optimum solutions of stopping the attack, protecting the restorers

and cleaning the fungal spread. A joint decision was taken on installing sensors to monitor the microclimate.

During the restoration process, this co-operation was continued with tests in the laboratory and on-site,

regarding the optimum cleaning treatments and prevention of reccurrence of fungal attacks.

The observations regarding the differentiated decay of paint layers needed extension of preliminary

chemical analyses by co-operation with the National Restoration Laboratory in Bucharest.

At the same time, we started co-operating with the Faculty of Sciences at „Lucian Blaga” University

of Sibiu, where they tested physical methods of stopping the decay and experimented new fungicide

solutions based on herbal extracts. Senior undergraduates of Biology were included in these experiments.

The paper underlines the importance of interdisciplinary co-operation in the process of restoration

and the necessity of continuing the research throughout our work.

38  

Middle and long-term microbial monitoring of bio-cleaned wall paintings at Monumental Cemetery of Pisa

Giancarlo Ranalli, Gabriele Alfano, Giuseppe Lustrato

Dip. Scienze e Tecnologie per l'Ambiente ed il Territorio (DISTAT), Università degli Studi del Molise, 86090 Pesche (IS), Italy ranalli@unimol.it

A recent success of the elimination of one of the major problems in the restoration of the wall

paintings of Monumental Cemetery, at Pisa (Italy), was based on the removing of the old degraded animal

glue used to detach the frescoes after the second war, and of the adherent on the fragile paint layers. The

innovative method showed the direct application of selected bacteria, Pseudomonas stutzeri A29 strain, on

“The Conversion of St. Efisio and the battle” fresco (XIV century, 3.5m x 7.8m) by Spinello Aretino, was a

fast and reliable tool for the altered glue removal (Ranalli et al., 2005). The action of bacteria showed

significant results in 12 hrs, (initial cells suspension of 108/ml), removing about 90% of degraded glue, and a

subsequent use of a specific protease. Viable bacteria are able to produce inducible enzymes when they

come in contact with the molecules to be broken down; these enzymes are not available on the market

(Antonioli et al., 2005). Moreover, the action of bacteria was monitored in real time and by measuring the

animal glue content by a GC/MS procedure (Andreotti et al., 2006). In order to confirm the new approach, to

validate data and to define an adequate protocol, middle (3 yrs) and long term (5 yrs) microbial monitoring on

the surface of bio-cleaned fresco were carried out. Microbial viable count by non-destructive velvet impinger

and ATP contents by luminescence were adopted. No presence of re-colonization and absence of microbial

risk in act. The most significant results confirm that the use of viable bacteria for the bio-cleaning of artworks

is a new safety biotechnology that offers a different approach and alternative procedure to the people

working to conserve and preserve our Cultural Heritage.

References

Ranalli, G., Alfano, G., Belli C., Lustrato G., Colombini M.P., Bonaduce I., Zanardini E., Abbruscato, P., Cappitelli F., Sorlini C., J. Appl. Microbiol. 2005, 98, 73-83.

Antonioli, P., Zapparoli G., Abbruscato P., Sorlini C., Ranalli G., Rigetti G., Proteomics 2005, 5, 2453-2459.

Andreotti A., Bonaduce I., Colombini M.P., Gautier G., Modugno F., Ribechini E., Anal. Chem. 2006, 78, 4490-4500.

39  

Determining acetic and formic acid vapor concentrations in museum environments by an improved ion chromatographic method with revised acid diffusion

coefficients

Robyn E. Hodgkins1, Alexander K. Tucker-Schwartz1, Cecily M. Grzywacz2, Robin L. Garrell1 1Department of Chemistry and Biochemistry & California NanoSystems Institute, University of California, Los Angeles, Box 951569, Los Angeles, CA 90095-1569 2The Getty Conservation Institute, 1200 Getty Center Drive Suite 700, Los Angeles, CA 90049-1684

Acid vapors induce corrosion on many materials. In museums, acetic and formic acid vapors cause

damage to natural objects and artifacts. Wood outgases acetic and formic acids that react with materials,

such as metals and calcium carbonate, to form corrosion salts, also known as efflorescence. If the objects

are not protected, continued exposure can lead to their complete destruction. An improved ion

chromatographic (IC) method has been developed to assay acetic and formic acid vapors captured by

passive air samplers. Additionally, new acid vapor diffusion coefficients were calculated using an updated

model based on vapor-liquid equilibrium theory and experimental measurements from model systems. The

diffusion model accounts for the presence of acid dimers and uses corrected activity coefficients. Passive

samplers were used to collect air samples from galleries in the Getty Villa Museum. The acid vapor

concentrations in the galleries were determined using the improved IC method and calculated diffusion

coefficients. Significantly elevated levels of acetic acid were found in one ventilated gallery that contained

four large wooden statues. This demonstrates that acid vapor measurements should be conducted, even in

ventilated rooms, to assess whether outgassing objects produce sufficient vapor to harm at-risk objects. The

described acid vapor detection and quantification method, although developed for museum analysis, is not

limited to these environments and can be applied to other environments or experimental systems.

40  

ADVANCING ANALYTICAL TECHNOLOGIES

41  

On the joint use of portable X-Ray Fluorescence and Laser-Induced Breakdown Spectroscopy in Archaeometallurgy

M.Ferretti1, S.Legnaioli2, G.Lorenzetti2, A. Foresta2, L.Pardini2 and V.Palleschi2

1Istituto per le Tecnologie Applicate ai Beni Culturali, Via Salaria, km 29.300, c.p.10, 00016 Monterotondo St. – Roma, Italy 2Applied Laser Spectroscopy Laboratory, Istituto di Chimica dei Composti Organometallici, Area di Ricerca di Pisa, Via G.Moruzzi 1, 56124 Pisa, Italy marco.ferretti@itabc.cnr.it, vincenzo.palleschi@cnr.it

Most of the applications reported in the literature for elemental analysis of ancient metals refer to

laboratory measurements, which in general imply the transfer of the object to the laboratory and/or sampling.

This procedure may have important disadvantages: according to the circumstances, the artistic relevance of

the object may forbid sampling, whereas its fragility and/or its dimensions may forbid transportation. The use

of portable, non-destructive instrumentation for in situ micro-analysis appears the most straightforward

solution to the above mentioned problems. In recent years, the authors of this communication developed an

experimental strategy involving the joint use of XRF (X-Ray Fluorescence) and LIBS (Laser-Induced

Breakdown Spectroscopy). Both these techniques are characterised by easy transportability of the

instrumentation, are non-destructive as they do not require sampling, and are able to provide quantitative

analytical information in very short measurement times. However, in the presence of heavily corroded

surfaces – quite common in bronze archaeological artefacts, for example - it has to be pointed out that such

quantitative information may not coincide with the bulk composition that, in principle, is what one is looking

for. In fact, it is well known that the presence of surface deterioration layers affects XRF measurements and

prevents a reliable achievement of the bulk composition. Although LIBS measurements of the bulk

composition are possible, this result is usually achieved at the cost of an increase of the surface micro-crater

produced by the laser. Deeply corroded bronzes may require to protract ablation to reach the bulk, which

would result in a higher damage of the piece. It’s thus important devising a method that would benefit both by

the intrinsic non-destructivity of the XRF technique, and by the capability of LIBS of performing true bulk

composition measurements even in the presence of heavy surface deterioration. The results presented in

this communication will show that if a portable XRF spectrometer is used as a non-destructive sniffer to drive

the choice of LIBS measurement points, significant information can be gathered with respect to such aspects

as fabrication context and technology, deterioration mechanisms, etc., of archaeological and historical

metals, guaranteeing at the same time a substantial reduction of the overall number of ablations.

Consequently, the impact on the piece is reduced as well.

42  

An innovative technique for investigating the degradation of plastic artifacts

R. Olmi, M. Bacci, C. Cucci, M. Picollo, S. Pieri, S. Priori Institute of Applied Physics, National Research Council, Via Madonna del Piano, 10, 50019 Sesto Fiorentino (Florence), Italy

An innovative methodology for identifying non-destructively the nature of plastic artifacts and their

level of deterioration is described. The purpose is that of determining the health status of plastic objects of

art, e.g. those created with synthetic polymers and constituting the contemporary art collections that are

prone to a substantial and frequently fast physical degradation.

The methodology is based on dielectric spectroscopy, i.e. on the investigation of the dielectric

properties of plastic materials over a sufficiently wide frequency range. The dielectric properties of a material

are related to its molecular structure, in particular to the presence of polar groups which are able to orientate

themselves when immersed in an electric field. Dielectric spectroscopy has the unique feature, among the

spectroscopic techniques, of covering an extremely wide frequency range, reasonably from 10-2 to 1010 Hz.

In such a wide range, it is possible to observe the behavior of the electric dipole moment associated with

different molecular structures: large macro-molecules consisting in long chains relax at very low frequencies,

while smaller molecules (for example, short chains or terminals) exhibit a dielectric relaxation at several kHz

or also at higher frequency values. On the other side, an investigation of the very high frequency portion of

the spectrum is also of interest: both amorphous and crystalline polymers exhibit absorption dipolar

dispersion in the microwave region (i.e. over 100 MHz); impurities, additives and fillers also give rise to

dispersions in that frequency range.

The rationale of the proposed methodology is the observation that the dielectric properties depend

on the molecular structure of a plastic material and, as such, they are sensitive to chemical and physical

changes due to ageing and/or degradation. A growing literature confirms this assertion: dielectric studies on

different plastic materials have demonstrated the effect of photo degradation, UV exposition, heat, water

absorption and natural/artificial ageing, on their dielectric characteristics. Based on these findings, dielectric

spectroscopy appears as promising approach to carry out non-invasive investigations of plastic artworks.

Dielectric spectroscopy (DS) results can be synergistically integrated with those coming from other well

established techniques used for polymer identification, such as NIR and FTIR spectroscopy.

As a starting point for the development of a portable DS characterization instrument, a database of

the low- frequency dielectric properties of 50 standard plastic materials (Resinkit®) has been setup.

Moreover a classification of polymeric materials based on the measured dielectric parameters (dielectric

constant and dielectric losses) is proposed for identification of polymers and as a reference for future

measurements on the same materials subjected to artificial ageing procedures. Work is in progress on the

design of a portable time-domain DS system for the on-site investigation of plastic artifacts in the very-low

frequency range, where the maximum dielectric sensitivity is expected.

This research has been partially supported from the European Community Seventh Framework Programme

FP7/2007-2013 under grant agreement n° 212218, POPART Project.

43  

44  

Effects of low-fluence laser irradiation on mural paintings: test studies on a fresco and a

secco model samples

A. Andreotti1, A. Cecchi2, G. Cecchi3, M.P. Colombini1, C. Cucci3, O. Cuzman4, C. Fornacelli3, M. Galeotti5, F.

Gambineri2, I. Gomoiu6, D. Lognoli3, D. Mohanu6, L. Palombi3, S. Penoni7, M. Picollo3, D. Pinna5, V. Raimondi3*, P. Tiano4, C. Todaro7, G.Valentini2

1 Chemistry and Industrial Chemistry Department (DCCI) - University of Pisa, Pisa, Italy 2 Laboratori ARCHA s.r.l., Pisa, Italy 3 Applied Physics Institute ‘Nello Carrara’ - National Research Council (CNR-IFAC), Firenze, Italy 4 Institute for the Conservation and Promotion of Cultural Heritage - National Research Council (CNR-ICVBC), Firenze, Italy 5 Opificio delle Pietre Dure (OPD), Firenze, Italy 6 National Art University of Bucharest, Bucharest, Romania 7 Faberestauro s.r.l., Firenze, Italy

The Laser Induced Fluorescence (LIF) technique is widely applied in several fields as a diagnostic tool to

characterise different materials on the basis of their fluorescence properties. Such technique can be attractive also

for a non-destructive investigation of mural paintings as far as employed materials and deterioration processes (e.g.

biodeterioration) are concerned. Nevertheless, no systematic data are available in the literature on the effects of

low-fluence laser irradiation on mural paintings. Most studies, in fact, are mainly focussed on the application of

lasers to the cleaning of cultural assets and consequently often explore ranges of laser fluences and emission

wavelengths which are not suitable for methods finalised to the diagnostics of the cultural heritage.

This paper presents a study devoted to investigate the feasibility of non-destructive diagnostics – based on

low-fluence UV laser radiation – on mural paintings. This study was carried out in the frame of the TDT-Bioart

Project – funded by the Regione Toscana – which aims to the development of novel methodologies for the

diagnostics and treatment of biodeteriogens on cultural assets. The study investigated different types of painted

surfaces – prepared either with a fresco and a secco techniques and using different pigments and binders - after

irradiation using an UV laser emitting at 355 nm with fluences ranging from 0.1 mJ/cm2 to 1 mJ/cm2. Different

analytical techniques – colorimetry, optical microscopy, Fiber Optical Reflectance Spectroscopy (FORS),

Attenuated Total Reflectance (ATR) microscopy and gas cromatography/mass spectrometry (GC/MS) - were

applied to the tested samples to compare the morphological and physico-chemical properties before and after laser

irradiation. Results open good prospects for a non-destructive investigation of the fluorescence properties of mural

paintings using UV laser radiation.

45  

Development of new systems for the preparation of paint cross sections

B. Brunetti1,2,3, E. Catelli4, R. Mazzeo4, C. Miliani2,3, S. Prati4, F. Rosi1,2, G. Sciutto4, A. Sgamellotti1,2,3 1 INSTM Operative Unit of Perugia c/o Dip.di Chimica, Università di Perugia, via Elce di Sotto 8, I-06123 Perugia, Italy

2 Centro di Eccellenza SMAArt, c/o Dip. di Chimica, Università degli Studi di Perugia 3 Istituto CNR-ISTM, c/o Dipartimento di Chimica, Università degli Studi di Perugia 4 University of Bologna Ravenna Campus, Microchemistry and Microscopy Art Diagnostic Laboratory, Via Guaccimanni 42, Ravenna, Italy

The identification and spatial location of the different organic materials in a paint cross section is

highly influenced by the sample preparation method. Sample is in fact generally embedded in a polymeric

material (i.e. epoxidic or acrylic) and subsequently polished in order to obtain a cross section. Unlikely this

methodology can interfere in the characterisation of the organic substances when for instance micro FTIR is

employed because the signal of the embedding material may overlap the ones derived by the sample. So far

several methods have been studied for the preparation of thin or stratigraphic section with FTIR transparent

salts (AgCl, KBr). However the debate on sample preparation is still open due to the fact that the proposed

methods have some limitations. Moreover also the polishing procedure may be of the outmost importance in

order to reduce the superficial roughness and optimise the analytical results which may be accomplished for

instance with FTIR microscopy (optimisation of the contact with the ATR crystal, reduction of the diffuse

reflection). Up to now different polishing system has been experimented such as Fast Ion Milling (FIM), but a

standardised and repeatable procedure has not being developed.

The aim of this contribution is to show the on going studies on two embedding systems to prevent

the embedding resins pollution based on the use of KBr or of cyclododecane as pre-consolidant before the

embedding procedure. Different polishing methods have also been considered such as wet and dry

polishing, microtomy, Argon Ion Milling to optimise the superficial sample morphology. The samples have

been observed under confocal microscopy, scanning electron microscopy and analysed in FTIR microscopy

both in ATR and in reflection.

Acknowledgements

The following research has been funded by the national project PRIN 08 “Setting up of diagnostic

methodologies for the stratigraphical characterisation and spatial location of the organic components in

artistic and archaeological polychrome works of art “and by the European project “CHARISMA” Cultural

heritage Advanced Research Infrastructures: Synergy for a Multidisciplinary Approach to

Conservation/Restoration, FP7 INFRASTRUCTURE n.228330.

46  

 

 

 

 

 

 

 

 

 

POSTERS

   

47  

Technological Examination of Composition of Transferred Grounds of Italian Paintings (XV-XVI centuries) from The State Hermitage Museum Collection

Irina. S. Artemieva1, Kamilla B. Kalinina1, Ilaria Bonaduce2, Maria Perla Colombini2, Victor A. Korobov1

1The State Hermitage Museum, Saint Petersburg, Russia 2 Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Italy kkalinina@mail.ru The State Hermitage Museum painting collection includes several oil paintings that were

transferred from their original wood support to a fabric one. Among them, there are some paintings from

Italian artists, such as Lorenzo Lotto, Cima da Conegliano, Bonifacio Veronese, Jacopo Palma il Vecchio.

The reason for transferring the paintings to the new support was connected with the climatic

conditions of Russia. During most of the year, in fact, artificial heating is necessary, resulting in a significantly

reduced relative humidity in museum environments. As a consequence, paintings that were painted in Italy

and then brought to Russia were moved to completely different climatic conditions. Most of the paintings

created by Italian painters were painted on a rather thick poplar wood, which is quite soft and hygroscopic

compared with, for example, oak wood. The wooden boards of the paint supports were thus subject to big

dimensional variations following fluctuations of the atmospheric humidity. As a result, paint grounds, whose

elasticity was different from that of wood, began to crack, lost adhesion and in some cases eventually

crumbled apart.

The first transferring in Russia was carried out by Pfandzelt in 1768, who transferred a painting from

wood to a copper support. Transferring the paintings became quite common in the first half of the 19th

century, and strongly increased during the second half of the 19th century. The greatest contribution to such

a complex technical task was made by restorers as A. Mitrochin, B. Peronard, A. Sidorov and his brothers, F.

Tabunzov. These restorers have been working in different periods, and each of them had their own

restoration techniques. So far, the transferred paintings show different conservation conditions.

Unfortunately, the majority of restoration archives have not survived. Now, after more than a century, some

of the paintings that were transferred need to undergo under conservation treatments, and diagnostic

campaigns were thus undertaken.

Inorganic materials were studied by means of SEM-EDX. The main pigments used were lead white

and zinc white. Sometimes the ground was applied in more than one layer. Some restorers, for example A.

F. Mitrochin and A. Sidorov, used colour primings of different thickness applied between the ground and the

original painting.

Organic materials were analysed with a GC-MS analytical procedure that permits the

characterisation of glycerolipid, proteinaceous and resinous materials. It was found that the main organic

materials used as binders were drying oils, egg, natural resins or their mixtures.

   

48  

The characterization of ancient materials: new perspectives offered by Electron Backscatter Diffraction (EBSD)

Arianna Gambirasi1,2, Elti Cattaruzza2, Monica Favaro1, Paolo Guerriero1, Luca Peruzzo3, Pietro A. Vigato1

1 Istituto di Chimica Inorganica e delle Superfici, Consiglio Nazionale delle Ricerche, Corso Stati Uniti 4 35127 Padova, Italy 2 Dipartimento di Chimica Fisica, Università Ca' Foscari Venezia, via Torino 155/b, I-30172 Venezia–Mestre, Italy 3 Istituto di Geoscienze e Georisorse, Consiglio Nazionale delle Ricerche, Via Matteotti, 30 35137 Padova, Italy

The study of materials of historical and artistic interest is mostly carried out on extremely small

samples collected from works of art. From these findings as much information as possible must therefore be

obtained by taking a multi-analytical approach that involves the sequential application of complementary

techniques useful to characterize both the organic and inorganic components.

While the analytical techniques for the analysis of organic components have achieved high reliability,

and very good detection limits, we can not say the same for crystalline and inorganic components. The main

limitation to accurate characterization of different mineral phases of such compounds is related to their micro

or nanometric size that often makes inappropriate the usual investigative techniques (eg.: X-ray diffraction).

Furthermore, in order to obtain exhaustive information on a particular sample, the different

techniques must be applied to the same specimen. This allows also a reliable evaluation of advantages and

limits of the different methodologies by a correct comparison of the different measurements.

The electron backscattering diffraction (EBSD) is a recently developed technique that, applied to a

conventional electron microscope gives information closely related to the crystal lattice of the material

analyzed. This information can provide the characterization of crystalline texture, the identification of phases,

the measure of the crystal grain properties (orientation, shape and grain size, grain boundaries), the

detection of microstructural deformation, with a spatial resolution of less than 100 nm from inorganic samples

of crystalline nature.

Thanks to its characteristics the EBSD is extremely useful to solve problems in the field of materials

science where this technique is mainly used for the study of metals and alloys, ceramic materials and

superconductors.

The materials of historical and artistic interest, i.e. painted layers, stone materials and their

degradation products, are mostly composed of crystalline and amorphous materials in heterogeneous

matrices, then the EBSD represents a powerful tool to obtain more detailed information on the crystalline

components of this category of samples at micro and nano scale dimensions, helping to improve

understanding of the processes of alteration and degradation of materials in works of art, throwing light on

the crystallization mechanisms, going to physical, chemical and biological conditions under which the crystal

growth occurred, and the subsequent modifications undergone by the material.

49  

The data acquired by EBSD from samples of inorganic pigments arranged in stratigraphic section will

be presented, explaining the methods of sample preparation developed in order to meet the requirements of

flatness and lack of surface roughness that ensure good quality patterns.

   

50  

Binding media analysis of some Romanian glass icons

Márta Júlia Guttmann 1, Václav Pitthard 2, Martina Griesser 2, Olimpia Coman-Sipeanu 3

1 Babes-Bolyai University, Faculty of Chemistry and Chemical Engineering, Arany János 11, RO-400028 Cluj Napoca, Romania, 2 Conservation Science Department, Kunsthistorisches Museum, Burgring 5, A-1010 Vienna, Austria 3 ASTRA Museum, Piaţa Mică 11-12, RO-550182 Sibiu, Romania mguttmann@chem.ubbcluj.ro

Transylvanian glass icons represent a highly specific and very valuable part of Romanian folk art.

There is very few scientific information available on these objects since no throughout technological study of

the glass icons was performed yet. The poster will present the first relevant binding media analyses of

several glass icons performed by gas chromatography and mass spectrometry (GC-MS), first at the

Conservation Science Department of the Kunsthistorisches Museum (Fine Arts Museum) in Vienna, then at

the Organic Chemistry Department of the Faculty of Chemistry and Chemical Engineering, Babeş-Bolyai

University in Cluj-Napoca. The analyses are part of an ongoing Ph.D. thesis focusing on the technological

research of ASTRA Museum’s glass icon collection (the largest collection of this kind in Romania).

According to the glass painting tradition, egg tempera was the usual binder of reverse painting on

glass. The analyses performed until now confirm more or less this technique, showing also some

particularities in case of certain regions or icon painters.

   

51  

Wood tar and wood resinous extracts as ingredients of Egyptian embalming materials: a GC/MS study.

J.J. Łucejko, F. Modugno, E. Ribechini, M.P. Colombini

Department of Chemistry and Industrial Chemistry, University of Pisa, Italy

jlucejko@gmail.com

Studying the chemical composition of organic biomaterials associated to archaeological artefacts can

give an important contribution both to archaeological and ethnographic studies and to a better knowledge

and conservation of the objects.

Wood-derived substances as wood tar, wood pitch and resinous wood extractives can be

encountered as ingredient of mummification balms used in ancient Egypt in funerary rituals and for the

preservation of the body. Analyses of the remains of resins, tars and pitches can answer questions relating

to their botanical natural origins, in addition to their modes of acquisition, preparation and geographical

provenience.

In particular, the use of pitch obtained from conifer wood and of terpenic resins as colophony and

mastic has been reported, and the use of terpenic materials obtained from cedar wood has been

hypothesized, also on the base of historical documents [1,2].

Plinius and Herodotus (Plinius the Elder Historia Naturalis libro XVI; Erodotus, Storie II 76-88; Diodorus

Siculus, Bibliotheca Historica) cite a “pix liquida” derived from a wood called “cedrium” as a material used in

Egypt for mummification, that has been interpreted as cedar wood.

In this context, we compared by GC/MS the composition of terpenic extracts and pitch obtained from

pine (Figure 1) and cedar wood, before and after induced ageing.

The research included also scientific investigation of Egyptian embalming materials, obtained from

archaeological expeditions in Egypt carried out by Department of Historical Sciences of the Ancient World of

University of Pisa, and sampled from archaeological remains conserved at the Natural History Museum of

University of Florence and from the Museum of Anatomy of University of Pisa. The results were interpreted

and compared with reference materials in order to assess the origin of the substances used to prepare the

embalming mixtures.

52  

Figure 1 GC-MS profiles of the acidic fraction of a) fresh pine resin b) hard-heated pine resin.

References [1]. M. Serpico, R. White, Chemical analysis of coniferous resins from ancient Egypt using gas chromatography/mass spectrometry (GC/MS), Proceedings of the seventh international congress of Egyptology, Cambridge, 1995

[2]. J. Koller, U. Baumer, Y. Kaup, U. Weser, Herodotus' and Pliny's embalming materials identified on ancient Egyptian mummies, Archaeometry 47 (2005) 609-628.

   

12.00 16.00 20.00 24.00 28.00 32.00

i.s.

i.s.

neoabietic ac.

abietic ac.

dehydroabietic ac.

levopimaric ac.

palustric ac.

12.00 16.00 20.00 24.00 28.00 32.00

12.00 16.00 20.00 24.00 28.00 32.00

i.s.

i.s.

neoabietic ac.

abietic ac.

dehydroabietic ac.

levopimaric ac.

palustric ac.

12.00 16.00 20.00 24.00 28.00 32.00

dehydroabietic ac.

abietic ac.

19-norabietatetraene

19-norabietatriene

retene7-oxo-dehydroabietic ac.

i.s.

i.s.

12.00 16.00 20.00 24.00 28.00 32.00

dehydroabietic ac.

abietic ac.

19-norabietatetraene

19-norabietatriene

retene7-oxo-dehydroabietic ac.

i.s.

i.s.

a

b

53  

Multi - method approach of an overpainted post Byzantine icon belonging to the Byzantine Christian Museum of Greece.

Agni Vasileia Terlixi1, Ilaria Bonaduce2, Maria Perla Colombini2, Anna Lluveras2, Eleni Ioakimoglou3, Jenny

Perdikari4, Athanasios Karabotsos3 1 Department of Conservation, National Gallery of Greece - Alexandros Soutzos Museum, 1 Michalakopoulou str., 11601 Athens, Greece 2 Dipartimento di Chimica e Chimica Industriale, Università di Pisa, Italy 3 Physicochemical Laboratory, Technical Educational Institute of Athens, Department of Restoration of Arts and Antiquities, 10-12 Aghiou Spyridonos str., 12210 Egaleo, Athens-Greece. 4 Icons conservation studio, Department of Conservation, Byzantine and Christian Museum, Athens, Greece

The present work reports the results of a multi analytical study of the icon “Panagia Kardiotissa”

(Byzantine Christian Museum collection) which is attributed to the famous hagiographer Aggelos (active in

the 1st half of 15th century).The icon depicts the Virgin Glycofilousa at the type of Kardiotissa. The general

artistic style of the icon strongly refers to the painting technique of Aggelos, though the background and the

inscriptions present features of folk art and are thus considered over-paintings.

The scientific examination of both the over-painted background and the original painting layers by

means of microscopic, chromatographic and spectroscopic techniques was considered to be a crucial step

for both assuring an suitable restoration process and to improve the historical knowledge of the icon.

Special attention was paid to the use of non- destructive methods since the icons artistic value and

condition did not permit the collection of many samples.

Visible Light and Fluorescence Light microscopy (VLM & FLM) were used for the detailed study of the

stratigraphy of the icon at selected areas. Organic materials were determined by Gas Chromatography

coupled to Mass Spectrometry (GC-MS) by means of a recently set-up procedure that allows the

characterization of lipids, waxes, resins, proteins and polysaccharide materials in the same paint micro

sample and in the presence of interfering inorganic materials. Staining of cross sections with dyes (as Amido

Black) and fluorophore markers (as FITC), was used for the in situ detection of proteinaceous media

throughout the layers. Finally, the inorganic pigments present at the various paint layers were identified by

using Energy Dispersive X- ray micro analysis (SEM/EDX) applied to selected cross-sections.

The multi-analytical approach used led to fruitful information regarding the materials and the painting

technique of the icon and the materials used for the over-painting .

In particular, VLM and FLM proved very useful for the clarification of the structure of the over-painted areas.

In some areas this over-painting consisted of a single dark blue layer and in others of both a light blue and a

dark blue layer. SEM/EDX indicated the presence of Prussian blue (firstly used at 1724) in these layers.

Staining the cross-sections with fluorophores clearly indicated the presence of proteinaceous media as

binder in these layers.

GC/MS allowed to identify the different materials (animal glue, egg, milk, shellac, Pinaceae resin,

fruit tree gum, and mastic resin). Combining the information gained by the GC-MS analysis of several sub-

samples containing different layers with those obtained with the staining tests performed on cross-sections, it

was also possible to establish the distribution of the organic materials in the different layers.

54  

In conclusion, the multi analytical approach used permitted to understand the composition of the

painting, layer by layer, allowing the reconstruction of the painting technique of the icon.

   

55  

A new tool for the assessment of ancient ceramic production technologies. ToF-SIMS investigation of the ceramic impasto in fragments from the archaeological site

of Quartaia (Italy).

Antonio Tognazzi1,2, Gemma Leone1, Agnese Magnani1, Marianna Aggravi1,2, Arduino Massimo Dattilo1,2, Luca Bracchini1,2 and Claudio Rossi1,2

1 Dipartimento Farmaco Chimico Tecnologico, University of Siena, Via Aldo Moro, 2-53100 Siena, Italy 2 Inter-University Center for Colloid and Surface Science – CSGI, Via della Lastruccia, 3-50019 Sesto Fiorentino (FI), Italy

The study of ancient ceramic fragments provides important information about a population. The

analysis of technological features (ceramic impasto and firing) and attributes (shape, size, decoration, etc.)

allows for the understanding of the complexity of the production process, degree of specialization and social

complexity of the civilizations that created them.

In this work, ancient ceramic fragments, dating back to the mid-sixth century B.C. and discovered in

1997 [1] in the archaeological site of Quartaia (Tuscany, Italy), were examined to obtain chemical and spatial

information on inorganic and organic components.

Time-of-flight secondary ion mass spectrometry (ToF-SIMS), atomic absorption spectroscopy(AAS)

and scanning electron microscopy (SEM) were used to study two types of ceramics having different impasto

(depurata and non-depurata ceramics) [2].

The potential of ToF-SIMS for the study of glassy and ceramic materials is well known [3–5] as well

as its complementarity with electron microbeam analyses, but its high spatial resolution and the ability to

measure simultaneously a wide range of elements down to trace levels make ToF-SIMS the most suitable

tool for the analysis of any small and precious sample [6].

The results revealed the presence of the major elements, i.e. Al, Mg, Na, K, Ca, Si, Fe; minor

elements, i.e. Cr, Cu, Mn, Pb; and organic components adsorbed during the firing process, both in depurata

and non-depurata ceramics. In addition, through ToF-SIMS imaging, it was possible to highlight inorganic

components, i.e. Na, Ca, Fe, K and Mg, that showed an inhomogeneous spatial distribution in non-depurata

ceramics. These chemical elements appear to be concentrated inside the inclusions of the non-depurata

ceramics impasto. Our studies verified that residues of organic components have a homogeneous spatial

distribution both in depurata and non-depurata ceramics impasto. The organic matter showed the presence

of dioxins, PCBs or lactones formed during the oxidation of lingo-cellulosic material, and penetrated into the

ceramic body during the firing process. In addition, the proposed method evidenced a strong correlation

between the chemical distribution of major and minor elements inside a ceramic impasto and the ceramic

production technology. These unique results demonstrated that ToF-SIMS is a potential tool to reveal

important aspects of the Quartaia ceramic production technology and it results in a very promising technique

for the archaeological studies.

References

56  

[1] M. Manganelli, E. Pacchiani, Atti delle giornate di studio “Città e territorio in Etruria. Per una definizione di

città nell’Etruria Settentrionale” 12–13 Marzo 1999, Grafiche Boccacci, Colle di Val d’Elsa (SI), Italy, 2002.

[2] Antonio Tognazzi et al., Surf. Interface Anal. 2010, in press, DOI 10.1002/sia.3286

[3] E. Ciliberto et al., Microsc. Microanal. Microstruct. 1995, 6, 533.

[4] S. Daolio et al., Rapid Commun.Mass Spectrom. 2001, 15, 1.

[5] D. S. McPhail et al., Microchim. Acta 2008, 161, 387.

[6] D. Rost et al., Meteorit. Planet. Sci. 2009, 44, 1225.

   

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Characterization of Polymers Used in Artworks by Pyrolysis Chromatography and Mass Spectrometry

Shuya Wei, Valentina Pintus, Manfred Schreiner

Institute of Natural Sciences and Technology in Art, Academy of Fine Arts, Schillerplatz 3, 1010 Vienna, Austria sywei66@hotmail.com

The mainly used synthetic products in artworks are acrylics, alkyds, and polyvinyl acetates.

However, other classes including nitrocellulose, polyurethane, silicon resin etc. have also been employed. It

is evident that contemporary artists can choose from an incalculable variety of commercially available

products, as single product or mixtures of them. The possibility to identify the enormous diversity in

materials used in modern art has important implications for their preservation. Pyrolysis Chromatography and

Mass Spectrometry (Py-GC/MS) has been applied for the characterization of polymers normally used in the

artworks including acrylics, alkyds, polyvinyl acetate (PVA) and polyurethane (PU) etc. Applying the

knowledge to the unknown samples from artworks and comparing the results with literature, different

polymers and especially the mixtures of them can be identified in one Py-GC/MS analysis.

In this presentation, the characterization of three samples from contemporary arts made by Franz

West – an Austrian contemporary artist is reported. In one sample, a mixture of PVA/Veova, alkyd and silicon

resin could be identified; copolymers of ethyl acrylate (EA), methyl methacrylate (MMA) and butyl

methacrylate (BMA) as well as Di-n-octyl phthalate (DOP) were detected in another sample; in the third

sample, PVA, alkyd as well as additives of phosphoric acid tris (3-methylpheny) ester and Diisobutyl

phthalate (DIBP) were determined. These results demonstrate that the developed Py-GC/MS procedure can

be used to identify a wide range of modern materials in artworks.

   

58  

Identification of a survived polychromy of the Apollo statue in Villa Corsini (Florence)

Pietro Baraldi1, Fabrizio Paolucci2, Andrea Rossi3

1Department of Chemistry, University of Modena and Reggio Emilia, Italy 2Galleria degli Uffizi, Florence, Italy 3Laboratory of imagine diagnostic, Modena, Italy pietro.baraldi@unimore.it

On the hills of Florence a new museum, in connection with the Galleria degli Uffizi, has been recently

opened. It exposes a series of important statues of different chronology and provenance. During the

preparatory phases for the opening of the museum, a research was begun for the study of the survival of

polychromy on the statues surface.

The problem is not simple, since many artworks, especially in the past, were strongly restored with

aggressive means and thereby the small areas with colors were erased. Therefore, in order to take into

consideration these possibilities, the study was thought as non invasive and non destructive as far as

possible. The employ in situ of portable and transportable instrumentation was taken into account. Among

the techniques considered there was Raman microscopy that, due to its high spatial resolution, could give a

detailed description of the colored areas discovered. Visible, ultraviolet and infrared imaging were also

considered, in order to obtain the complete representation of the artworks and to identify the areas were

colors are now absent, but binders residues are still present. Moreover digital microscopy was used in the

aim of observing closely the surface in search of very small traces of the polychromy.

By carefully examining the surface of the statue of Apollo, dating from the second century a.D. and found

probably in Rome, it was clear that the body was completely treated with acids in a past restoration, for

obtaining the supposed white surface of the classic artworks; however, the head, broken from the body and

found elsewhere, have an interesting polychromy, observable by naked eye too. The eyes are clearly traced

in black color, the hair is abundantly painted with a yellow-brown pigment, the neck has an ochre hue and

the lips have still on their margins some traces of a pale red color.

The imaging with ultraviolet and infrared light revealed other areas with persistence of polychromy.

The analysis by Raman spectroscopy showed that yellow and red ochres were used for the hair, possibly

with yellow on the prominences and red for the background, so as to put in evidence a blond hair. Inside this

painting layer however vermilion was also found . The eyes were painted black with carbon of vegetal origin.

The neck color was obtained by mixing a white chalk with vermilion and the lips with red ochre. The red of

the head, based on hematite, reveal to be amorphous, as when the compound is obtained by heating yellow

ochre or when a fire occurred. Gypsum is present in many areas and can be formed by sulfatation of the

calcite.

Traces of lead white reveal that the surface of the marble was made uniform by treating it with

cerussa and a binder. Traces of synthetic pigment red 22 reveal a preceding retouching.

59  

        

Raman spectrum from the head of Apollo    

60  

Non-destructive analysis of polychromed terracotta sculptures from the 15th and 16th centuries by portable XRF

A. Kriznar2, M.V. Muñoz1, F. de la Paz1, M. A. Respaldiza2 and M. Vega1

1 Museo de Bellas Artes de Sevilla, Seville, Spain 2Centro Nacional de Aceleradores, Universidad de Sevilla, Seville, Spain

In Spain not many large-size polychromed sculptures made in terracotta have survived until today

due to its fragile material. However, the Fine Arts Museum of Seville has a beautiful collection of several

artworks made by prestigious homeland and foreign sculptors. Among them the most interesting are Lorenzo

Mercadante de Bretaña and his pupil Pedro Millán who belong to the most important medieval artists that

worked in Andalusia in the second half of the 15th and the beginning of the 16th centuries, as well as Pietro

Torrigiano, an Italian sculptor and Michelangelo’s contemporary who came to Seville in the first half of the

16th century. The Museum of Fine Arts in Seville has an exceptional collection of some of their big terracotta

sculptures, among which are Mercadante’s “Virgin and Child” (2/2 15. Cent.) and three Millan’s works,

“Entombment of Christ” (around 1490), “Christ Male of Sorrows” (1485-1503) and “Christ bound to the

coloumn”(2/2 15.Cent.). There is also a small sculpture of Pietá (16th century), which belongs to Millán´s

circle. On the other hand, Pietro Torrigiano is the author of two majestic artworks made around 1525, “Saint

Hyeronimus” and “Virgin of Nativity”.

All mentioned sculptures except the “Pietá” are human-size, with partially well conserved

polychromy, which was in part restored during previous interventions. Only the sculpture “Christ bound to the

coloumn” by Millán had to be completely reconstructed and conserves no colour. The pigments applied in all

these sculptures were of interest, as well as later interventions. The sculptures are part of the Museum’s

permanent exhibition and can not be removed for their place. That is why a non-destructive portable X-ray

Fluorescence equipment was used directly in situ, in collaboration with the National Centre of Accelerators

(University of Seville). In some cases it was combined with UV light study. The XRF equipment has an X-ray

tube of 30 kV with anode of W and one SDD detector with energy resolution of 140 eV.

The analysis gave important information on the pigments applied. In all the sculptures we can find

similar colour palette: lead white (Pb), yellow and red ochre’s (Fe), vermillion (Hg), azurite (Cu), some copper

based green pigment, umbra (Mn, Fe) and an organic black pigment. In some cases also lead-tin yellow was

detected. Many decorative parts of the sculptures were gilded, while in “Christ Male of Sorrows” also a thin

silver foil was applied. Especially sculptures by Millán were re-polychromed at least one time and some of

them are covered with thick layer of wax and resin. In several sculptures Ba, Ti, Zn and Cd were discovered

in various areas, showing retouches with modern Ti-Zn white, litophone and cadmium red. The sculpture of

“Saint Hyeronimus” was restored almost in the entire surface, as proved with UV light and XRF analysis. The

results served not only for the pigment analysis, but also revealed a tight connection between Mercadante

and Millan.

Acknowledgements

61  

We acknowledge the financial support from the Projects of Excellence 205/HUM-493 and HUM

04544 of Junta de Andalucía.

   

62  

Multispectral Imaging and Colorimetric Analysis of the ‘Adoration of the Child’, by the Master of the Castello Nativity

S.Legnaioli1, A. Gioli2, R.V. Iungo2, G.Lorenzetti1, P. Nieri3, L.Pardini1 and V.Palleschi1

1Istituto di Chimica dei Composti Organometallici - Area di Ricerca del CNR - Via G.Moruzzi, 1 – 56124 Pisa 2 Dipartimento di Storia delle Arti – Piazza San Matteo in Soarta 2 – 56100 3Museo Nazionale di San Matteo - Lungarno Mediceo, 1, 56127 Pisa

The ‘Adoration of the Child’, attributed to Master of the Castello Nativity (a painter active in Florence

between 1450 al 1475) was originally located at the Church of St. Johns of the Augustinians in Leghorn and

then, at the end of XIX century, moved to the local Civic Museum. The painting (also known as the ‘Madonna

Dantesca’ because of the quotation of the first verses of the XXXIII canto of the Dante’s Paradise on the

border of a tent besides the Virgin) underwent last year a delicate restoration intervention at the Museum of

St. Matthew, in Pisa. In collaboration with the restorers of the Museum and the Department of History of Arts

of the University of Pisa, a campaign of measurements was planned in order to follow the various stages of

the restoration. In particular, high resolution multispectral and infrared images were acquired before, during

and after the restoration; at the same time, a detailed colorimetric analysis was performed on the pigments,

also in view of the monitoring of the painting after its return at the Civic Museum in Leghorn.

Fig. 1 – Visible and IR images of the painting before the restoration

   

63  

An integrated approach to painting diagnostics: the case-study of two Vasari panels

Luciano Marras, Anna Pelagotti, Emanuela Massa Art-Test; Via del Martello 14, 56100, Pisa, Italy; via del Ronco, 12, 50125, Firenze, Italy marras@art-test.com

Integrated, non-invasive technical examinations of paintings and artworks can provide information

about materials and techniques used by artists. They may also reveal the extent of old damages now

concealed by past restoration. Moreover, they can supply important art historical facts that can help to

identify artists, assist in dating and to uncover forgeries. Thus the results of this kind of investigations enable

the detailed planning of targeted conservation activities, and support the monitoring and recording of their

execution phases. These analyses are carried out with portable non-invasive instruments, i.e. without the

need of moving the artwork from its location and without extracting any sample from it. Both the optical

instruments (result of a thorough and complex study and carried out with the objective of optimizing both

performance and portability) designed and realized in-house by Art-Test, the use of new methodologies (e.g.

the Multilayer, patented) and the approach we purpose here to analyse and compare a wide range of

different diagnostics data allows us to optimise the obtained results. We here present the interesting case-

study provided by two large panel paintings of Giorgio Vasari, where scanning IR reflectography,

multispectral and multilayer analysis, thermography, X-ray radiography, ED-XRF and other techniques show

interesting information at different depths, i.e. related to different layers of the artworks.

   

64  

Characterization of Ararat cochineal

Yeghis Keheyan ISMN-CNR, c/o Dept. of Chemistry, University “La Sapienza”, p.le Aldo Moro 5, Rome-0185, Italy

Natural dyes may be classified to different criteria; the most important of which for analytical

purposes is their chemical composition.

Most important among these was a red dye, the highly prized “Armenian red”, which rivalled royal

purple in value. This dye was prepared from the Armenian cochineal insect called vordan in Armenian, late

known by its name of kirmiz (Turkish). The insect was found in the Armenian cities of Artashat and Dvin were

particularly renowned for its production. In this paper we report the examination of some naturally occurring

organic dyes performed by Pyrolysis gas chromatography mass spectrometry, Laser desorption FTICR and

FTIR techniques. Experimental dyes were prepared using old recipes from Armenian fonts.

   

65  

 

The browning of stained glass windows: characterization of Mn-rich bodies and evaluation of cleaning methods

Simone Cagno1, Simone Bugani4, Gert Nuyts1, Kristel de Vis2, Joost Caen2, Lukas Helfen3, Marine Cotte3

and Koen Janssens1 1University of Antwerp, Department of Chemistry, Universiteitsplein 1, B-2610 Wilrijk, Belgium 2Artesis Hogeschool, Department Conservation-Restoration, Blindestraat 9, B-2000 Antwerpen, Belgium 3ESRF, Rue Jules Horowitz 6, F-38043 Grenoble, France 4University of Bologna, Department of Industrial Chemistry and Materials, Viale del Risorgimento 4; 40126 Bologna, Italy

Mn-rich bodies can be found in the alteration layer of ancient glass objects and cause the surface to

turn brown to black. Historical glass contains a natural quantity of manganese in the Mn(II) or Mn(III)

oxidation states. In the Mn-containing bodies, instead, manganese is in the Mn(IV) state. Both internal and

external sources of Mn have been hypothesised to explain this phenomenon. In restoration practice, dark

surface layers are converted into colourless ones with the application of reducing solutions.

In this work the shape and distribution of the Mn-bodies are studied and the effectiveness of different

glass restoration methods is assessed. Fragments of glass windows dated to the 14th century, originating

from the Canterbury Cathedral (UK) were examined with high resolution computed tomography, performed

with synchrotron radiation at ESRF, beamline ID19 and µ-XANES at ESRF, beamline ID21. The same

samples were analysed before, during and after the treatment with products used in common restoration

practice, with different concentrations and application time, in order to have a ‘real time’ monitoring of the

treatment. The results obtained provide useful information in view of a correct conservation approach of

glass artefacts.

   

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Beeswax and saccharides in Roman wall paintings at Herculaneum: original materials?

A. Andreotti1, M.P. Colombini1, A. Lluveras1*, F. Piqué2, G. Torraca2

1 University of Pisa, Chemistry and Industrial Chemistry Department, via Risorgimento 35, 56126 Pisa 2 Herculaneum Conservation Project, Scavi di Ercolano, via Mare 44, 80056 Ercolano (NA)

The Herculaneum Conservation Project (HCP) is a Packard Humanities Institute project, in

collaboration with the Soprintendenza Speciale per i Beni Archeologici di Napoli e Pompei and the British

School at Rome, for the conservation and enhancement of the archaeological site of Herculaneum [1]. Within

the HCP project, an investigation started a few years ago aimed at studying wall painting techniques in

Herculaneum in order to inform conservation interventions. One research strand focused on the paintings in

the House of the Bicentenary, one of the most important on site, and, for comparison, on samples from a

recently excavated room at the Villa of the Papyri. The two sites differ in conservation history as the House

of the Bicentenary underwent several interventions involving application of surface coatings, the first

immediately following excavation, while the samples from the Villa of the Papyri have not been treated at all

in modern times. Today, the paintings in the House of the Bicentenary present severe and on-going

deterioration problems.

The characterization of the materials, part of the diagnostic study, was conducted initially with

imaging techniques and non-invasive methods [2]. These analyses revealed the ubiquitous presence of

organic material possibly beeswax, with oxalates and sulfates salts.

The characterization of the organic materials presented herein, was performed by

chromatography/mass spectrometric techniques (Py-GC/MS, GC/MS); it confirmed the presence of beeswax

but revealed in addition the presence of egg, possibly used as binder in the decorative parts of the paintings

but not in the red and yellow monochrome backgrounds.

The comparison with the samples from untreated wall paintings of the Villa of the Papryi showed a

different organic material composition mainly characterized by the absence of beeswax in all layers.

An interesting result is related to the presence of saccharides identified in samples from both sites,

mainly in the plaster layers. Their interpretation is difficult because saccharides may be formed by chemical

degradation of plants fibers and/or microorganisms. However the addition of small amounts of ‘sugars’ as

fluidizers to Roman plasters has been hypothesized, although their chemical identification in Roman wall

paintings has not been previously reported.

References

[1] Conservation and Management of Archaeological Sites. Special edition on Herculaneum, Anno 8, numero 4; 2007.

[2] Indagini non-invasive sulle pitture del Tablino della Casa del Bicentenario ad Ercolano’; in Materiali e Strutture, Anno V, numero 9-10; pp. 6-27; 2007.