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

What is Paper?

Paper = a thin mat of intertwining fibers

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

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

Outline Handmade Paper Machine-made Paper Blue Paper Newspaper “Acidic” Paper Kraft Paper Ph Testing Shameless Self-Promotion

Handmade Paper

Screening Pulp from a Vat

Drying sheets of paper

Laid Paper

Made one sheet at a time in a frame or mould

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

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

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

Laid Paper Made one sheet at a time in a frame or mould Laid lines = Closely-spaced parallel lines formed by rows of metal wires in the mould Chain lines = Bolder parallel lines about one to two inches apart formed by thicker wires that secure the laid wires to the mould Watermark = Distinguishable letter, image, or symbol incorporated into paper during the manufacturing process Grain is parallel to the chain lines

A Paper Mould

Laid Lines

A Paper Mould Chain Line Laid Lines

A Paper Mould Chain Line Laid Lines Water Mark

Viewing a watermark

Watermark designs

1742 English Book

1742 Book: laid & chain lines

1742 Book: watermark

Machine-Made Paper

Fourdrinier Machine

1798: continuous paper-making machine developed in France

Fourdrinier Machine 1798: continuous paper-making machine developed in France 1804–7: first machines built in England

Fourdrinier Machine 1798: continuous paper-making machine developed in France 1804–7: first machines built in England 1817: machine imitated in U.S.

Fourdrinier Machine 1798: continuous paper-making machine developed in France 1804–7: first machines built in England 1817: machine imitated in U.S. 1827: first true Fourdrinier machine in U.S.

Fourdrinier Machine 1798: continuous paper-making machine developed in France 1804–7: first machines built in England 1817: 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

All machine-made paper is wove paper

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

Wove Paper All machine-made paper is wove paper Pulp is poured or sprayed onto a continuous wire mesh conveyor mounted on rollers Uniform wire mesh creates even density

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

Wove Paper All machine-made paper is wove paper Pulp is poured or sprayed onto a continuous wire mesh conveyor mounted on rollers Uniform 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 Roll” Creates a watermark on wove paper

Wove Paper Watermark (1823)

Blue Paper

Early Blue Paper

Venetian Blue (15th–16th centuries)

Early Blue Paper Venetian Blue (15th–16th centuries) Bleue Hollande (17th–18th centuries)

Early Blue Paper Venetian Blue (15th–16th centuries) Bleue Hollande (17th–18th centuries) Prussian Blue dye introduced in early 1700s

Early Blue Paper Venetian Blue (15th–16th centuries) Bleue Hollande (17th–18th centuries) Prussian Blue dye introduced in early 1700s Indigo: most widespread dye in textile and paper production

Early Blue Paper Venetian Blue (15th–16th centuries) Bleue Hollande (17th–18th centuries) Prussian Blue dye introduced in early 1700s Indigo: most widespread dye in textile and paper production –Insoluble in water, so it requires chemical additives like urine to break down –Indigo 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

Spike in U.S. production, 1840s–1860s

19th Century Blue Paper Spike in U.S. production, 1840s–1860s Recycling of Levi Strauss’s denim jeans?

19th Century Blue Paper Spike in U.S. production, 1840s–1860s Recycling of Levi Strauss’s denim jeans? –No, Levi’s denim introduced in the 1870s

19th Century Blue Paper Spike in U.S. production, 1840s–1860s Recycling of Levi Strauss’s denim jeans? –No, Levi’s denim introduced in the 1870s 1828: Discovery of synthetic urea in Germany

19th Century Blue Paper Spike in U.S. production, 1840s–1860s Recycling of Levi Strauss’s denim jeans? –No, Levi’s denim introduced in the 1870s 1828: Discovery of synthetic urea in Germany 1830s: Use of indigo in the textile industry expands rapidly

19th Century Blue Paper Spike in U.S. production, 1840s–1860s Recycling of Levi Strauss’s denim jeans? –No, Levi’s denim introduced in the 1870s 1828: Discovery of synthetic urea in Germany 1830s: Use of indigo in the textile industry expands rapidly 1840s: Recycled indigo rags become paper

1854 Blue Laid Paper

1854 Blue Wove Paper

Newspaper

17th & 18th century: Newspapers printed in limited numbers on hand-made laid paper

Newspaper 17th & 18th century: Newspapers printed in limited numbers on hand-made laid paper 1810s: European machine-made paper enables newspapers to be printed cheaply in larger quantities

Newspaper 17th & 18th century: Newspapers printed in limited numbers on hand-made laid paper 1810s: European machine-made paper enables newspapers to be printed cheaply in larger quantities 1850s: newspapers still +-100% rag content

Newspaper 17th & 18th century: Newspapers printed in limited numbers on hand-made laid paper 1810s: European machine-made paper enables newspapers to be printed cheaply in larger quantities 1850s: newspapers still +-100% rag content 1880s: wood pulp largely replaces cotton pulp

1818 N.Y. Evening Post Printed on cotton rag wove paper

1830 New York Mirror Printed on cotton rag wove paper

“Acidic” Paper

Increasing Acidity of Paper

1840s: Mechanical wood pulping machines developed in Germany

Increasing Acidity of Paper 1840s: Mechanical wood pulping machines developed in Germany 1867: Use of calcium bisulfite to chemically pulp wood patented in the U.S.

Increasing Acidity of Paper 1840s: Mechanical wood pulping machines developed in Germany 1867: 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 Paper 1840s: Mechanical wood pulping machines developed in Germany 1867: Use of calcium bisulfite to chemically pulp wood patented in the U.S. 1874: First commercial sulfite pulping mill built in Sweden –Dominant method of pulping wood into the 1930s –Results in a paper with high acid content

1864 Confederate newsprint

Made 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

1879: Invented in Germany (Kraft = strength)

Kraft Process 1879: Invented in Germany (Kraft = strength) 1890: First Kraft pulp mill built in Sweden

Kraft Process 1879: Invented in Germany (Kraft = strength) 1890: First Kraft pulp mill built in Sweden Uses sodium sulfide to chemically break down wood chips into paper pulp

Kraft Process 1879: Invented in Germany (Kraft = strength) 1890: First Kraft pulp mill built in Sweden Uses sodium sulfide to chemically break down wood chips into paper pulp Produces stronger paper with less lignin than the sulfite process--less likely to discolor

Kraft Process 1879: Invented in Germany (Kraft = strength) 1890: First Kraft pulp mill built in Sweden Uses sodium sulfide to chemically break down wood chips into paper pulp Produces stronger paper with less lignin than the sulfite process--less likely to discolor By 1940 is dominant method of pulping wood

Kraft Process 1879: Invented in Germany (Kraft = strength) 1890: First Kraft pulp mill built in Sweden Uses sodium sulfide to chemically break down wood chips into paper pulp Produces stronger paper with less lignin than the sulfite process--less likely to discolor By 1940 is dominant method of pulping wood Well suited to pulping resinous wood like pine

Ph Testing

Ph Testing Pens Results are often difficult to interpret

Ph Testing Kit Use with clean, Ph neutral, distilled water

1799 Document

1799 document = Acidic

Two 1801 documents

The chemical make up and storage history of each document has produced different aging characteristics

100% Rag Paper Doesn’t necessarily mean Acid-Free!

Why Does Paper Break Down?

Acids present in 18th century paper, too

Why Does Paper Break Down? Acids present in 18th century paper, too Lignin (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, too Lignin (an organic polymer) present in old papers, too, but more common in wood pulp paper Conservators now think it’s the sizing

Sizing Agents

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

Sizing Agents Size: substance applied to paper to control its absorbency and/or to smooth its finish –Hard sized paper = writing paper –Weak sized paper = newsprint –Unsized paper = blotter paper

Sizing Agents Size: substance applied to paper to control its absorbency and/or to smooth its finish –Hard sized paper = writing paper –Weak sized paper = newsprint –Unsized paper = blotter paper Gelatin (animal) sizing used for centuries

Sizing Agents Size: substance applied to paper to control its absorbency and/or to smooth its finish –Hard sized paper = writing paper –Weak sized paper = newsprint; –Unsized paper = blotter paper Gelatin (animal) sizing used for centuries Rosin sizing introduced in 1820s

Sizing Agents Size: substance applied to paper to control its absorbency and/or to smooth its finish –Hard sized paper = writing paper –Weak sized paper = newsprint; –Unsized paper = blotter paper Gelatin (animal) sizing used for centuries Rosin sizing introduced in 1820s Alum (acidic) sizing introduced in 1870s

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