ansi cgats tr016 2012

ANSI/CGATS TR 016-2012

An ANSI Technical Report

Prepared by

Committee for Graphic Arts Technologies Standards (CGATS)

Graphic technology — Printing Tolerance and Conformity

Assessment

SECRETARIAT NPES THE ASSOCIATION FOR SUPPLIERS OF PRINTING, PUBLISHING AND CONVERTING TECHNOLOGIES APPROVED JANUARY 30, 2012 AMERICAN NATIONAL STANDARDS INSTITUTE, INC.

1899 PRESTON WHITE DRIVE RESTON, VIRGINIA 20191 TEL: 703/264-7200 FAX: 703/620-0994 www.npes.org

ANSI CGATS TR 016-2012

ii © NPES 2012 – All rights reserved

ANSI TECHNICAL REPORT

Publication of this Technical Report, which has been registered with ANSI, has been approved by the Committee for Graphic Arts Technologies Standards (CGATS) in accordance with the CGATS Procedure for Development of an ANSI Technical Report. This document is not an American National Standard and the material contained herein is not normative in nature. This Technical Report was developed in cooperation with Print Properties and Colorimetric Working Group of IDEAlliance. Questions and comments regarding this Technical Report should be addressed to the CGATS Secretariat, NPES The Association for Suppliers of Printing, Publishing and Converting Technologies, 1899 Preston White Drive, Reston, Virginia 20191. Copyright © 2012– NPES The Association for Suppliers of Printing, Publishing and Converting Technologies All rights reserved. No part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without the prior written permission from NPES.


© NPES 2012 – All rights reserved iii

Contents Foreword .................................................................................................................................................. iv

Introduction ................................................................................................................................................ v

1. Scope ................................................................................................................................................... 1

2. Normative references ........................................................................................................................... 1

3. Terms and definitions .......................................................................................................................... 1

4. Overview ............................................................................................................................................. 2

5 Assessment of individual aspects of conformity ................................................................................. 3

6 Combined conformity assessment metric ............................................................................................ 5

7. Annexes

Annex A (Informative) Derivation of conformance assessment — deviation tolerances .......................... 6

Annex B (Informative) Derivation of conformance assessment — within-sheet variation tolerances ...... 7

Annex C (Informative) Derivation of conformance assessment — production variation tolerances ........ 8

Bibliography .............................................................................................................................................. 9


iv © NPES 2012 – All rights reserved

Foreword This CGATS Technical Report was prepared by the members of CGATS Subcommittee 3, Metrology & Process Control, in cooperation with the members of the GRACoL Working Group and the IDEAlliance Print Properties and Colorimetric Council. At the time of its approval, the following were the Participating Members and Observers of CGATS SC3.

CGATS Chairman: Raymond Cheydleur CGATS Vice Chairman: Steve Smiley Secretary: Debbie Orf

Participating Member Representative Observing Member Representative Arizona State University Howard E Nelson Alliance Group Mr. Tom Cooper CGS Publishing Technologies Intl. Heath Luetkens Allison Systems Corporation Jean M Jackson Flexographic Technical Assoc., Inc. Joe Tuccitto

Steve Smiley Anasys Instruments Khoren Sahagian Arizona State University Penny Ann Dolin

FUJIFILM North America Corp. Lawrence C. Warter Bowling Green State University Charles Spontelli Global Graphics Software Kenneth Elsman Color Sciences, LLC Jim Burns Hewlett Packard Company Charles Jia ColorMetrix Technologies, LLC James J. Raffel IDEAlliance Joe Fazzi Dalton & Robinson Tim Dalton Individual Walter F. Zawacki Datacolor Kenny Thomas JUST Normlicht Inc. Eric Dalton Diageo Kevin Chop Konica Minolta Business Solutions Ellen C Carter Doppelganger L.L.C. William B Birkett Lexmark International, Inc. Ann L McCarthy EastWest Creative John Owens manroland AG Andreas Lorenz Epson America, Inc. Roy Bohnen NPES David Q. McDowell EskoArtwork David Harris Printing Industries of America

Mark Bohan Greg Radencic

Flexographic Technical Assoc., Inc. Mark Cisternino Flexographic Technical Assoc., Inc. Rose K. McKernon

QuadTech, Inc. John Seymour Flint Group Cindy Harbin RGB Metrology, LLC Lawrence C. Steele Fundacion Gutenberg, Inst.

Argentino de Artes G. Ignacio N GaglianoneMarcela Rojas RMG Consulting Richard Goodman

RIT Robert Chung RR Donnelley Michael A. Rodriguez Graphic Packaging Corporation Jeff Kobin Society for Imaging Science & Tech. David Q. McDowell Graphics Microsystems Inc. Steve Headley Sun Chemical Corporation Danny C. Rich Heidelberg U.S.A. Charles Koehler Vertis Communications Steve Smiley IDEAlliance David J. Steinhardt X-Rite, Incorporated Raymond W.

Cheydleur Individual Amrut Kulkarni

Zwang & Company David L. Zwang Individual Adam Dewitz Individual Bill Pope Individual Dave Prouty Individual David C. Albrecht National University of Singapore Du Xian

PBM Graphics Jim Brisendine

Quad/Graphics Donna Biss

QuadTech Greg Wuenstel

Specialty Graphic Imaging Association Dutch Drehle

Time, Inc. Kin Wah Lam

X-Rite Kelly VandenBosch


© NPES 2012 – All rights reserved v

At the time this Technical Report was approved, the members and officers of IDEAlliance were as follows: Chairman: Steve Smiley Vice Chairman: Mike Rodriquez

Organization Representative Organization Representative

Aldertech Bruce Bayne INX International Ink Co. Javier Robles

California Polytechnic State Univ. Xiaoying Rong JUST Normlicht, Inc. Eric Dalton

CGS Publishing Technologies, Intl Heath Luetkens Komori Hal Stratton

ColorMetrix Technologies, LLC James Raffel Konica Minolta Jeff Collins

EFI Digital Print Solutions John Nate Konica Minolta Russell Doucette

Ellis Consulting Ron Ellis La Cross Litho Supply Matt Fehn

Epson America Roy Bohnen Menasha Corporation Scott Vanden Boom

Fineeye Color Solutions John Sweeney Nazdar Tim Quinn

Flexographic Technical Assoc. Steve Smiley Nazdar Bruce Ridge

Fujifilm Don Schroeder Nazdar Mike Ruff

Fujifilm North America Corp. Lawrence Warter NPES David McDowell

George Kondogianis Consulting George Kondogianis Printing Industries of America Greg Radencic

Gotham Graphics Nubar Nakashian Quad Graphics Bob Hallam

Hallmark Cards Jeff Budd Bob Chung RIT

IDEAlliance Joe Fazzi William Garno RIT

IDEAlliance David Steinhardt RR Donnelley Mike Rodriguez

Individual Colleene Capola Ryerson University Abhay Sharma

Individual Dick Presley Sappi Fine Paper David Niles

Individual David Rapp Sun Chemical Corporation Danny Rich

Ink Systems, Incl. Paula Gurnee US Ink Dennis Cheeseman

INK International Ink. Co. Chuck LaFever X-Rite, Incorporated Raymond Cheydleur


vi © NPES 2012 – All rights reserved

Introduction Printing standards are being developed by ANSI CGATS and ISO TC130, Graphic technology. The standards being developed are based on two different approaches. The traditional approach is to define the color of the solids, two-color solid overprints and tone-value increase (TVI). The newer approach is to use a reference characterization data set to define the printing aims.

Specification of allowed tolerances on these aims is inconsistent and where they do exist take a one-size-fits-all approach. None of the standards provide any method by which individual normative requirement can be combined together to provide an overall evaluation of results. This makes evaluation of the conformance of a printed sheet, of a press run, or a printing operation difficult and inconsistent among the various organizations providing industry evaluation and certification services.

The goal of this technical report is to propose a conformance assessment procedure which includes evaluation of within-sheet variation, deviation, and production variation as well as a procedure for the combination of the weighted results into a single rank. Because a common procedure is required across a variety of printing processes and applications a three-level tolerance schema is also proposed. The various aspects of conformance assessment in combination with the three level tolerance schema can be used to evaluate the conformance of printed material to the reference color characterization data which was used as the intended printing aim.

While the assigned tolerances are in some ways arbitrary, they are based on statistical evaluation of real printing data obtained through the RIT Printing Standards Audit (PSA) survey database and a FOGRA Process Standard Offset (PSO) database of printing test data.


© NPES 2012 – All rights reserved 1

Graphic technology — Printing Tolerance and Conformity Assessment 1 Scope This technical report defines a process that can be used in evaluating the conformance of printed material to a set of reference color characterization data, which are used as the intended printing aim. It also provides a conformance assessment procedure which includes evaluation of within-sheet variation, deviation, and production variation as well as a three level tolerance schema for the combination of the weighted results into a single rank.

2. Normative references

ISO 13655, Graphic technology -- Spectral measurement and colorimetric computation for graphic arts images

ISO 12642-2, Graphic technology -- Input data for characterization of 4-colour process printing -- Part 2: Expanded data set

3. Terms and definitions For the purposes of this technical report the following terms and definitions apply:

3.1 color characterization relationship between input data values, typically CMYK, and color measured on the printed sheet, typically CIEAB data 3.2 conformity assessment demonstration that specified requirements relating to a product or process are fulfilled 3.3 deviation the color difference between the OK sheet and the reference characterization data set; deviation conformity is a verification of successful calibration whereby the deviation tolerance specifies the limits of acceptability 3.4 printing process method by which images are transferred to a substrate such as paper, including but not limed to offset, gravure, letterpress, flexography, electrophotography, ink-jet, etc. 3.5 production variation the ability of a printing system to maintain consistency between the same color patches printed in the same locations of the sheet over the press run; variation is the difference between “production samples” and aim 3.6 substrate-corrected colorimetric aims (SCCA) color characterization data that are corrected for the colorimetric difference between production and the reference substrate


2 © NPES 2012 – All rights reserved

3.7 OK sheet Production print singled out to be representative of the completion of the calibration process and used for deviation and within-sheet variation assessment NOTE: For measurement purposes, sequential sheets are often selected and their measurements averaged to minimize the effect of artifact and measurement variation. NOTE: OK sheet no longer involves a print buyer, but a set-up sheet, containing ISO 12642-2 target, selected to assess the status of a calibration. 3.8 tolerance permissive or maximum allowed quantitative differences 3.9 within-sheet variation color variation of the same color patches printed in different locations on a single press sheet 4 Overview The conformity assessment approach described in this Technical Report is applicable to any printing process for which the printing aims are defined through reference to color characterization data, and for which the characterization process can be appropriately modeled using a 4 channel CMYK target. While such data are usually defined by standards, technical reports, or other formal documentation, a characterization data set may also be privately defined by agreement between the parties involved in the printing contract. A default assumption is that the color characterization data are based on the ISO 12642-2 CMYK target and measurements of printed samples are made in accordance with ISO 13655. It is further required that where color characterization data are to be used with a substrate whose color differs from that contained in the color characterization data set, the substrate correction methodology defined in Appendix A of ISO 13655 is applied to produce substrate-corrected colorimetric aims (SCCA). These data are used for both the printing aims and conformity assessment. Three specific aspects of printing conformance are included. These are:

1. The ability of a printing system to be successfully calibrated as demonstrated by the color difference between the “First” sheet and the reference characterization data set. Called herein “deviation”

2. The within sheet or spatial uniformity of the printing process as demonstrated by the color variation of the same color patches printed in different locations on a single press sheet. Called herein “within-sheet variation”

3. The ability of a printing system to maintain consistency between the same color patches printed in the same locations on the sheet over the press run. Called herein “production variation”

In evaluating each of these aspects of conformity assessment it is important to identify the following:

a. The elements, i.e., color patches with known device CMYK values, to be measured

b. The measurement reference and metric to be used

c. Any necessary processing of the measurement data

d. The allowed tolerance or tolerances



Although measurements of printed samples are made in accordance with ISO 13655, inter-instrument agreement, e.g., one device has been used to calibrate the device, and another to perform conformity assessment, will be treated as a part of the deviation tolerance. In addition, in order to be most useful, these individual aspects of conformity assessment must be combined into a single conformance assessment metric. Because this conformity assessment approach is intended to cover a wide range of printing applications a multi-level tolerance approach has been included. The three levels are identified as Level A (stringent) tolerance for color critical applications and proofing; Level B (normal) tolerance for commercial printing; and Level C (relaxed) tolerance for pleasing color. The derivation of the numerical values assigned to each level for each aspect of conformance assessment is described in Annexes A, B and C. All colorimetric measurements are to be made according to ISO 13655 using the measurement condition and backing associated with the reference color characterization data being used. The tolerances in this procedure are based on the use of CIEDE2000 as defined in ISO 13655. The specifics of the elements to be measured, measurement references, data handling and allowed tolerances for each of the three individual aspects of conformity are described in Clause 5. The schema for the combination of the individual aspects of conformity assessment must be combined into a single conformity assessment metric are defined in Clause 6. 5 Assessment of individual aspects of conformity 5.1 Deviation conformity assessment Both deviation and within-sheet conformity assessment are based on measurement of the OK sheet which represents the calibration of the printing system to the characterization data set. Two metrics are required for the evaluation of deviation. These are (1) the color differences of all of the patches of the printed ISO 12642-2 target from the aim values and (2) the differences of selected key solids and tints of the printed ISO 12642-2 target, from the aim values. The cumulative probability of the differences of all patches is used as the evaluation tool for the full data set and the individual patches to be evaluated are listed in Table 1. Table 1 also shows the CIEDE2000 tolerances assigned to each measure for each conformance level.

Table 1 — Deviation metrics and tolerances

Target description Deviation tolerance (DE2000)

Level A Level B Level C 95th percentile of all patches of ISO

12642-2 3.0 4.0 5.0

Solid

100C 1.5 2.4 4.0 100M

100Y 100K 2.4 3.6 6.0

50% input tint

50C

1.5 2.0 2.5 50M 50Y 50K

Near-neutral 50C/40M/40Y 3.0 3.5 5.0

The derivation of the tolerances for the 95th percentile of all patches of the ISO 12642-2 target is shown in Annex A. The derivation of the tolerances for the solids is shown in Annex C.



5.2 Within-sheet conformity assessment There are many ways to estimate the within-sheet variation. The results depend on the number of redundant patches, their respective locations in the printed area, and their tonal values. In order to provide a common baseline for within-sheet variation assessment, the ISO 12642-2 target, containing 29 sets of CMYK values that appear twice within the target, is used. The cumulative probability of the color differences between the measured values of these redundant patches are used to determine within sheet variation. Table 2 lists the CMYK values and patch IDs of the redundant patches. Table 3 lists the allowed CIEDE2000 values for the 95th percentile for each conformance level.

Table 2 — Duplicate Patches in IT8.7/4 Target

# C M Y K ID 1 ID 2 # C M Y K ID 1 ID 2 1 0 0 0 0 1 1367 16 10 0 0 0 10 1302 2 0 0 10 0 82 1342 17 20 0 0 0 19 1300 3 0 0 20 0 163 1340 18 30 0 0 0 28 1298 4 0 0 30 0 244 1338 19 40 0 0 0 37 1297 5 0 0 40 0 325 1337 20 70 0 0 0 55 1294 6 0 0 70 0 487 1334 21 85 0 0 0 64 1291 7 0 0 85 0 568 1331 22 100 0 0 0 73 1287 8 0 0 100 0 649 1327 23 100 85 85 0 647 1368 9 0 10 0 0 2 1322 24 0 0 0 10 1362 1486

10 0 20 0 0 3 1320 25 0 0 0 20 730 1360 11 0 30 0 0 4 1318 26 0 0 0 40 946 1357 12 0 40 0 0 5 1317 27 0 0 0 60 1071 1355 13 0 70 0 0 7 1314 28 0 0 0 80 1096 1352 14 0 85 0 0 8 1311 29 0 0 0 100 1260 1347 15 0 100 0 0 9 1307

Table 3—Within-sheet metrics and tolerances

Target description Within-sheet variation tolerance (DE2000) 95th percentile of redundant patches

Level A Level B Level C 1.0 1.5 3.0

The derivation of the tolerances for the within-sheet variation is shown in Annex B.

NOTE: If there are significant within-sheet variations, this forms a limit to what deviation tolerance can be achieved, i.e, the two aspects of variation may not be independent. 5.3 Production variation conformity assessment

Because this test is generally performed on live work, the ISO 12642-2 target is too large in size to be useful. Therefore control or run bar targets need to be used. Table 4 shows the nine patches required for this evaluation and the tolerances, based on the 95th percentile of the cumulative probability of the samples selected for each patch.

The printing run should be sampled randomly over the length of the run and a minimum of 20 samples collected. The metric for production variation is the color difference between the measured values and the substrate corrected characterization data used as the aim for the printing.

Print buyers want consistent color printed in different locations and at different times. The best way to achieve within-run color consistency and run-to-run color consistency is to use printing aims, and not the OK sheet, as the reference.



Table 4 — Production variation metrics and tolerances

Target description Production variation tolerance (DE2000)

Level A Level B Level C

Solid

100C 1.5 2.4 4.0 100M

100Y 100K 2.4 3.6 6.0

50% input tint

50C

1.5 2.0 2.5 50M 50Y 50K

Near-neutral 50C/40M/40Y 3.0 3.5 5.0

The derivation of the tolerances for the production variation tolerances is shown in Annex C.

6 Combined conformity assessment metric Clause 5 lays out the metric and tolerances for the three individual aspects of conformity assessment — deviation, within-sheet variation, and production variation — and their sub-elements. However, to be meaningful these need to be combined into a single value ranking system. Because deviation, within-sheet variation, and production variation are not equally important, weighting functions must be developed both for the individual aspects and for the levels within each aspect. First, within any individual aspect, i.e., deviation, within-sheet variation, and production variation, the lowest level achieved for any sub-element, e.g., solids, tints, and near-neutral, is the level assigned to that aspect. The weighting factors for Levels are: Level A 3 Level B 2 Level C 1 Less than Level C 0 It is important to note that if any sub-element does not pass at least the Level C tolerance the complete individual aspect is assigned a value of 0 for the subsequent combining of individual contributions to the overall score. Once the score for the individual aspects have been assigned they are then combined using weighting functions for the individual aspects. The weighting functions for Aspects are: Deviation 3 Within sheet variation 1 Production variation 6 The overall conformance evaluation rank is the sum of the products of the score of individual aspects times the weighting functions for the aspects. For example if for a specific printing system evaluation each aspect achieved a Level A score (3) then the rank for that printing system evaluation would be 30 (3x3 + 1x3 + 3x6) or the maximum value. Other results would be combined in a similar manner. Different weighting factors, due to different printing processes and customer requirements, are allowed if prior agreement is obtained between all parties involved before copy preparation work is started. Where this conformance evaluation technique is used for single sheets, such as proofs or validation prints, only the deviation and within-sheet variation aspects are used to create an overall conformance value.



Annex A (Informative)

Derivation of conformance assessment — deviation tolerances

As defined earlier "deviation" is the color difference between the “First” sheet and the reference characterization data set. The allowed tolerances are based on the cumulative probability of all patches of the ISO 12642-2 target as well as specific limits, as specified in Table 4, on the solids and 50% tints of the CMYK colors and a mid-tone three color overprint. The derivation of the tolerances for the cumulative probability are based on the following analysis.

The PSA survey database at RIT (Chung and Chen, 2011) contains 35 sets of measurement data that was collected from sample sheets submitted as part of the survey. Each sheet contained two images of the ISO 12642-2 target which were measured and averaged for that sample. The DE2000 color differences between each sample and the reference characterization data were computed and tabulated. These data were then merged and the cumulative probability of the pooled database was tabulated with the results shown in Table A.1.

Table A.1. Cumulative probability of color difference of all patches of the PSA survey database

Cumulative Probability

DE2000

0% 0.0

5% 0.9

10% 1.2

15% 1.4

20% 1.6

25% 1.8

30% 1.9

35% 2.1

40% 2.3

45% 2.4

50% 2.6

55% 2.7

60% 2.9

65% 3.1

70% 3.3

75% 3.5

80% 3.7

85% 4.0

90% 4.4

95% 4.9

100% 8.0

The tolerance for deviation conformity is based on the following criteria: Level A (3.0 DE2000) corresponds to the 65th percentile of the distribution, Level B (4.0 DE2000) corresponds to the 85th percentile of the distribution and Level C (5.0 DE2000) corresponds to the 95th percentile of the distribution.



Annex B (Informative)

Derivation of conformance assessment — within-sheet variation tolerances

As defined earlier, "within-sheet variation" is the color variation of the same color patches printed in different locations on a single press sheet. The ISO 12642-2 target contains 29 sets of CMYK values that appear twice within the target. The cumulative probability of the color differences between the measured values of these redundant patches are used to determine within sheet variation. The same PSA Survey data base of 35 samples described in Annex A was also used to evaluate the variation of the color differences of the redundant patches. Table B.1 shows the cumulative probability of the pooled database of the 29 redundant patches.

Table B.1. Cumulative probability of color difference of the redundant patches of the PSA survey database


DE2000

0% 0.1

5% 0.1 10% 0.1 15% 0.1 20% 0.2

25% 0.2 30% 0.2 35% 0.2 40% 0.3

45% 0.3 50% 0.3

55% 0.4

60% 0.4 65% 0.4 70% 0.5

75% 0.6

80% 0.7

85% 0.8

90% 1.0

95% 1.4

100% 2.2

The tolerance for within-sheet variation conformity is based on the following criteria: Level A (1.0 DE2000) corresponds to the 90th percentile of the distribution, Level B (1.5 DE2000) corresponds to the 95th percentile of the distribution and Level C (2.5 DE2000) corresponds to the 100th percentile of the distribution.



Annex C (Informative)

Derivation of conformance assessment — production variation tolerances

As defined earlier production variation is the ability of a printing system to maintain consistency between the same color patches printed in the same locations on the sheet over the press run. The production variation tolerances for the solid CMYK values were are derived from a database containing 185 qualified jobs (courtesy of Fogra, 2011). Each of the 185 production runs contained 10 samples. These were individually compared to the substrate corrected aims of the individual printing runs and the DE2000 values computed for the CMYK solids. The pooled cumulative probability data is tabulated in Table C.1.

Table C.1. Cumulative probability of color difference of the solid patches of the FOGRA database


DE2000

C M Y K

0% 0.1 0.1 0.1 0.3

5% 0.4 0.3 0.3 0.8 10% 0.7 0.5 0.4 1.0 15% 0.8 0.5 0.5 1.1 20% 0.9 0.6 0.5 1.2

25% 1.0 0.7 0.6 1.4 30% 1.1 0.8 0.6 1.5 35% 1.3 0.9 0.7 1.6 40% 1.4 0.9 0.7 1.7 45% 1.5 1.0 0.8 1.8 50% 1.6 1.1 0.8 1.9

55% 1.7 1.2 0.9 2.1

60% 1.8 1.3 0.9 2.2 65% 2.0 1.4 1.0 2.4 70% 2.0 1.5 1.0 2.5 75% 2.2 1.5 1.1 2.6 80% 2.3 1.7 1.1 2.8 85% 2.4 1.8 1.2 3.0

90% 2.7 2.0 1.4 3.3

95% 3.3 2.3 1.5 3.7

100% 4.6 3.8 1.6 6.1

The tolerance for production variation conformity is based on the following criteria: Level A corresponds to the 75th percentile of the distribution, Level B corresponds to the 95th percentile of the distribution and Level C corresponds to the 100th percentile of the distribution.

Tolerances around tints and near-neutral, not available in the Fogra database, have been tested with limited datasets. It represents a reasonable starting point and further deliberation may be required.



Bibliography 1. ISO 12647-1: 2002 Graphic technology — Process control for the production of half-tone colour separations,

proof and productions prints — Part 1: Parameters and measurement methods

2. ISO 12647-2: 2004 Graphic technology — Process control for the production of half-tone colour separations, proof and production prints — Part 2: Offset lithographic processes

3. ISO 12647-4: 2005 Graphic technology — Process control for the production of half-tone colour separations, proof and production prints — Part 4: Publication gravure printing

4. ISO 12647-7: 2007 Graphic technology — Process control for the production of half-tone colour separations, proof and production prints — Part 7: Proofing processes working directly from digital data

5. ISO/DIS 12647-8: 2010 Graphic technology— Process control for the production of half-tone colour separations, proof and production prints— Part8: Validation print processes working directly from digital data

6. ISO DIS 15339-1: 2011 Graphic Technology — Printing from digital data; Part 1: Basic principles

7. ISO 13655: 2009 Graphic technology -- Spectral measurement and colorimetric computation for graphic arts images

8. Chung, Robert and Chen, Ping-hsu, Statistical Analysis of PSA Press Sheet Check-up Database, RIT Printing Industry Center, Rochester, NY, PICRM- PICRM-2011-08, 2011; available at: http://print.rit.edu/research/index

ansi cgats tr016 2012

Documents

tone colour separations

flexographic technical assoc

color characterization data

characterization data set

conformity assessment approach

corrected colorimetric aims

run color consistency

color patches printed