What is meant by "rag" paper?
Rag is a term used today to describe papers that contain cotton rags and linters. Rags come from the clippings used in the making of textiles and from the reprocessing of cotton garments. Linters are the by-product of the cotton gin process. They are shorter fibers that cling to the cotton seed after it is extracted by the cotton gin. This makes cotton rag a more environmentally-friendly option compared to tree-based papers.
There are also a number of other advantages to papers that are constructed of 100% cotton. First, cotton cellulose is up to 10 times stronger than wood cellulose. Cotton is also lignin free. Lignin that is left in tree-based papers will naturally turn yellow or brown over time.
Cotton paper has become the preference of many professional artists because of its purity, durability and permanence.