Rag paper

Rag paper is a category of paper that is made from a pulp of discarded textiles, rope and other fibre products. Rag paper in its various forms was a widely-used paper for most of the past two millennia. Production spread along the Silk Road from its early 2nd-century origin in China to the Islamic world by the 8th century. It was introduced into Christian Europe by the 12th century, and western Europe came to dominate rag production up until the mid-19th century, when rag paper was displaced in favour of far more cost-efficient pulpwood acidic paper.

Rag paper is valued today as a specialty paper for its archival quality and tear resistance compared to wood pulp paper. Modern rag paper is often cotton paper, made from cotton linters, with a usual pH of 6.4 and degree of polymerization of 1481.2.