Historically, most of society’s writings and visual images have been recorded on paper.
Paper made before the 19th century was often made by hand from linen and cotton rag materials which are excellent sources of high cellulose, long fibers. Gelatin, from animal hides, was used to size such papers and because the resulting papers were neutral to only slightly alkaline they had very good storage properties. The paper machine appeared at the end of the 18th century, and as the demand for paper outpaced sources of available gelatin, cotton rags and linen, wood fiber took the place of cotton and linen. However, wood has shorter fibers and lower cellulose content along with lignin so that chemical methods had to be developed to free fibers from wood and other plant matter to supply the increasing amounts of paper furnish needed. Mechanical action [“beating”] to soften and bleaching to whiten these new materials yielded pulps that could be laid down by machine as a sheet with subsequent drying to form paper.