Paper Identification 101Nic Butler, Ph.D.Charleston County Public LibrarySpecial Collections

What is Paper?

What is Paper?Paper = a thin mat of intertwining fibers

What is Paper?Paper = a thin mat of intertwining fibersTypically made from vegetable fibers composed of cellulose

What is Paper?Paper = a thin mat of intertwining fibersTypically made from vegetable fibers composed of cellulosePaper begins as a fibrous pulp separated from wood, cotton, grass, etc., by a mechanical or chemical or process

What is Paper?Paper = a thin mat of intertwining fibersTypically made from vegetable fibers composed of cellulosePaper begins as a fibrous pulp separated from wood, cotton, grass, etc., by a mechanical or chemical processPaper is an organic substance that breaks down over time and can become weak, brittle, and discolored

OutlineHandmade PaperMachine-made PaperBlue PaperNewspaperAcidic PaperKraft PaperPh TestingShameless Self-Promotion

Handmade Paper

Screening Pulp from a Vat

Drying sheets of paper

Laid Paper

Laid PaperMade one sheet at a time in a frame or mould

Laid PaperMade one sheet at a time in a frame or mouldLaid lines = Closely-spaced parallel lines formed by rows of metal wires in the mould

Laid PaperMade one sheet at a time in a frame or mouldLaid lines = Closely-spaced parallel lines formed by rows of metal wires in the mouldChain lines = Bolder parallel lines about one to two inches apart formed by thicker wires that secure the laid wires to the mould

Laid PaperMade one sheet at a time in a frame or mouldLaid lines = Closely-spaced parallel lines formed by rows of metal wires in the mouldChain lines = Bolder parallel lines about one to two inches apart formed by thicker wires that secure the laid wires to the mouldWatermark = Distinguishable letter, image, or symbol incorporated into paper during the manufacturing process

Laid PaperMade one sheet at a time in a frame or mouldLaid lines = Closely-spaced parallel lines formed by rows of metal wires in the mouldChain lines = Bolder parallel lines about one to two inches apart formed by thicker wires that secure the laid wires to the mouldWatermark = Distinguishable letter, image, or symbol incorporated into paper during the manufacturing processGrain is parallel to the chain lines

A Paper Mould

A Paper MouldLaid Lines

A Paper MouldChain LineLaid Lines

A Paper MouldChain LineLaid LinesWaterMark

Viewing a watermark

Watermark designs

1742 English Book

1742 English Book

1742 Book: laid & chain lines

1742 Book: watermark

Machine-Made Paper

Fourdrinier Machine

Fourdrinier Machine1798: continuous paper-making machine developed in France

Fourdrinier Machine1798: continuous paper-making machine developed in France18047: first machines built in England

Fourdrinier Machine1798: continuous paper-making machine developed in France18047: first machines built in England1817: machine imitated in U.S.

Fourdrinier Machine1798: continuous paper-making machine developed in France18047: first machines built in England1817: machine imitated in U.S.1827: first true Fourdrinier machine in U.S.

Fourdrinier Machine1798: continuous paper-making machine developed in France18047: first machines built in England1817: machine imitated in U.S.1827: first true Fourdrinier machine in U.S.Basis of modern papermaking machines

Fourdrinier Machine, 1850s

Fourdrinier Machine, early 1900s

Rolls of modern paper

Wove Paper

Wove PaperAll machine-made paper is wove paper

Wove PaperAll machine-made paper is wove paper Pulp is poured or sprayed onto a continuous wire mesh conveyor mounted on rollers

Wove PaperAll machine-made paper is wove paper Pulp is poured or sprayed onto a continuous wire mesh conveyor mounted on rollersUniform wire mesh creates even density

Wove PaperAll machine-made paper is wove paper Pulp is poured or sprayed onto a continuous wire mesh conveyor mounted on rollersUniform wire mesh creates even density Watermark can be created by using a dandy roll (with a soldered wire pattern)

Wove PaperAll machine-made paper is wove paper Pulp is poured or sprayed onto a continuous wire mesh conveyor mounted on rollersUniform wire mesh creates even density Watermark can be created by using a dandy roll (with a soldered wire pattern)Grain is harder to determine, but is usually parallel to the length of the sheet

1816 Wove Paper

1817 Laid Paper

Dandy RollCreates a watermark on wove paper

Wove Paper Watermark (1823)

Wove Paper Watermark (1823)

Wove Paper Watermark (1823)

Blue Paper

Early Blue Paper

Early Blue PaperVenetian Blue (15th16th centuries)

Early Blue PaperVenetian Blue (15th16th centuries)Bleue Hollande (17th18th centuries)

Early Blue PaperVenetian Blue (15th16th centuries)Bleue Hollande (17th18th centuries)Prussian Blue dye introduced in early 1700s

Early Blue PaperVenetian Blue (15th16th centuries)Bleue Hollande (17th18th centuries)Prussian Blue dye introduced in early 1700sIndigo: most widespread dye in textile and paper production

Early Blue PaperVenetian Blue (15th16th centuries)Bleue Hollande (17th18th centuries)Prussian Blue dye introduced in early 1700sIndigo: most widespread dye in textile and paper production Insoluble in water, so it requires chemical additives like urine to break downIndigo dye not suited to mass production of textiles

1742 English Book . . .

. . . was bound with Blue Laid Paper

1742 Blue Laid Paper (detail)

19th Century Blue Paper

19th Century Blue PaperSpike in U.S. production, 1840s1860s

19th Century Blue PaperSpike in U.S. production, 1840s1860sRecycling of Levi Strausss denim jeans?

19th Century Blue PaperSpike in U.S. production, 1840s1860sRecycling of Levi Strausss denim jeans?No, Levis denim introduced in the 1870s

19th Century Blue PaperSpike in U.S. production, 1840s1860sRecycling of Levi Strausss denim jeans?No, Levis denim introduced in the 1870s1828: Discovery of synthetic urea in Germany

19th Century Blue PaperSpike in U.S. production, 1840s1860sRecycling of Levi Strausss denim jeans?No, Levis denim introduced in the 1870s1828: Discovery of synthetic urea in Germany1830s: Use of indigo in the textile industry expands rapidly

19th Century Blue PaperSpike in U.S. production, 1840s1860sRecycling of Levi Strausss denim jeans?No, Levis denim introduced in the 1870s1828: Discovery of synthetic urea in Germany1830s: Use of indigo in the textile industry expands rapidly1840s: Recycled indigo rags become paper

1854 Blue Laid Paper

1854 Blue Wove Paper

Newspaper

Newspaper

Newspaper17th & 18th century: Newspapers printed in limited numbers on hand-made laid paper

Newspaper17th & 18th century: Newspapers printed in limited numbers on hand-made laid paper1810s: European machine-made paper enables newspapers to be printed cheaply in larger quantities

Newspaper17th & 18th century: Newspapers printed in limited numbers on hand-made laid paper1810s: European machine-made paper enables newspapers to be printed cheaply in larger quantities1850s: newspapers still +-100% rag content

Newspaper17th & 18th century: Newspapers printed in limited numbers on hand-made laid paper1810s: European machine-made paper enables newspapers to be printed cheaply in larger quantities1850s: newspapers still +-100% rag content1880s: wood pulp largely replaces cotton pulp

1818 N.Y. Evening PostPrinted on cotton rag wove paper

1830 New York MirrorPrinted on cotton rag wove paper

Acidic Paper

Increasing Acidity of Paper

Increasing Acidity of Paper1840s: Mechanical wood pulping machines developed in Germany

Increasing Acidity of Paper1840s: Mechanical wood pulping machines developed in Germany1867: Use of calcium bisulfite to chemically pulp wood patented in the U.S.

Increasing Acidity of Paper1840s: Mechanical wood pulping machines developed in Germany1867: Use of calcium bisulfite to chemically pulp wood patented in the U.S. 1874: First commercial sulfite pulping mill built in Sweden

Increasing Acidity of Paper1840s: Mechanical wood pulping machines developed in Germany1867: Use of calcium bisulfite to chemically pulp wood patented in the U.S. 1874: First commercial sulfite pulping mill built in SwedenDominant method of pulping wood into the 1930sResults in a paper with high acid content

1864 Confederate newsprint

1864 Confederate newsprintMade with inferior materials (probably a combination of cotton rag and wood pulp)

1859 Charleston Directory contains acidic paper

and some alkaline paper ...

and some acidic color adverts

and an advert for paper

Note the variety of laid and wove paper

1914 Acidic Paper

1931 acidic French paper

Kraft Paper

Kraft Process

Kraft Process1879: Invented in Germany (Kraft = strength)

Kraft Process1879: Invented in Germany (Kraft = strength)1890: First Kraft pulp mill built in Sweden

Kraft Process1879: Invented in Germany (Kraft = strength)1890: First Kraft pulp mill built in SwedenUses sodium sulfide to chemically break down wood chips into paper pulp

Kraft Process1879: Invented in Germany (Kraft = strength)1890: First Kraft pulp mill built in SwedenUses sodium sulfide to chemically break down wood chips into paper pulpProduces stronger paper with less lignin than the sulfite process--less likely to discolor

Kraft Process1879: Invented in Germany (Kraft = strength)1890: First Kraft pulp mill built in SwedenUses sodium sulfide to chemically break down wood chips into paper pulpProduces stronger paper with less lignin than the sulfite process--less likely to discolorBy 1940 is dominant method of pulping wood

Kraft Process1879: Invented in Germany (Kraft = strength)1890: First Kraft pulp mill built in SwedenUses sodium sulfide to chemically break down wood chips into paper pulpProduces stronger paper with less lignin than the sulfite process--less likely to discolorBy 1940 is dominant method of pulping woodWell suited to pulping resinous wood like pine

Ph Testing

Ph Testing PensResults are often difficult to interpret

Ph Testing KitUse with clean, Ph neutral, distilled water

1799 Document

1799 document = Acidic

Two 1801 documents

Two 1801 documentsThe chemical make up and storage history of each document has produced different aging characteristics

100% Rag PaperDoesnt necessarily mean Acid-Free!

Why Does Paper Break Down?

Why Does Paper Break Down?Acids present in 18th century paper, too

Why Does Paper Break Down?Acids present in 18th century paper, tooLignin (an organic polymer) present in old papers, too, but more common in wood pulp paper

Why Does Paper Break Down?Acids present in 18th century paper, tooLignin (an organic polymer) present in old papers, too, but more common in wood pulp paperConservators now think its the sizing

Sizing Agents

Sizing AgentsSize: substance applied to paper to control its absorbency and/or to smooth its finish

Sizing AgentsSize: substance applied to paper to control its absorbency and/or to smooth its finishHard sized paper = writing paperWeak sized paper = newsprintUnsized paper = blotter paper

Sizing AgentsSize: substance applied to paper to control its absorbency and/or to smooth its finishHard sized paper = writing paperWeak sized paper = newsprint Unsized paper = blotter paperGelatin (animal) sizing used for centuries

Sizing AgentsSize: substance applied to paper to control its absorbency and/or to smooth its finishHard sized paper = writing paperWeak sized paper = newsprint; Unsized paper = blotter paperGelatin (animal) sizing used for centuriesRosin sizing introduced in 1820s

Sizing AgentsSize: substance applied to paper to control its absorbency and/or to smooth its finishHard sized paper = writing paperWeak sized paper = newsprint; Unsized paper = blotter paperGelatin (animal) sizing used for centuriesRosin sizing introduced in 1820sAlum (acidic) sizing introduced in 1870s

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