Title slide: Nineteenth-Century American Paper: It's Not All Bad!
Slide 2: Until 1817 when the first paper machine was installed in an American mill, all paper manufactured in the United States was handmade. Traditionally, the fibrous pulp was prepared by selecting linen and hempen rags, and retting them in alkaline solutions. Once cleansed and softened, the rags were beaten and separated into individual fibers, creating pulp.
Slide 3: The degree of external sizing depended on use. If book or news paper, the percentage of gelatin in solution was low, and the paper was relatively absorbent. Thus, it was easily dampened before letterpress printing. If intended for intaglio printing, writing, or drawing, it was heavily sized. Because the gelatin size readily spoiled, the acid, aluminum sulfate (alum), was added every day to slow its deterioration.
Slide 4: Although not notable at the time, papers sized on different days now vary in acidity, color, and flexibility. These signatures might consist of "Saturday" and "Tuesday" paper.
Slide 5: Along with machinery, other advances, e.g., chlorine bleaching and internal alum-rosin sizing, dramatically improved the efficiency of papermaking and lowered costs. After the Civil War, rag pulp was augmented by chemical-wood pulp to make even less-expensive paper. By the end of the century, cheap groundwood paper was used for newspapers and other "ephemera."
Slide 6: Photochemically reactive lignin was not removed from groundwood pulp, and when combined with acidic alum-rosin sizing, it caused what now constitutes the "brittle paper" problem. It must be understood that this is a twentieth-century paper problem, not a nineteenth-century one. The mass deacidification of non-ligneous papers wastes precious resources, and, deacidification, while it may slow deterioration, does nothing to strengthen paper.
Last slide: From the Hand to the Machine: Nineteenth-Century American Paper and Mediums—Technologies, Materials, Characteristics, and Conservation by Cathleen A. Baker, to be published in Fall 2010, describes both hand and machine papermaking, as well as letterpress, intaglio, and lithographic printing; writing, drawing, and watercolor painting mediums; and decorated papers. Preservation and conservation issues involving these complex artifacts are also discussed. Please visit The Legacy Press website