Cotton paper

Cotton paper is made from cotton linters or cotton from used cloths (rags) were the primary material source, hence the name rag paper. Cotton paper is superior in both strength and durability to wood pulp-based paper, which may contain high concentrations of acids.

Properties

Certain cotton fibre paper is known to last hundreds of years without appreciable fading, discoloration, or deterioration;^[1] so it is often used for important documents such as the archival copies of dissertations or theses. As a rule of thumb, for each percentage point of cotton fibre, a user may expect one year of resisting deterioration by use (the handling to which paper may be subjected).^[2] Legal document paper typically contains 25% cotton. Cotton paper will produce a better printout than copy paper because it is able to absorb ink better.

Cotton paper is typically graded as 25%, 50%, or 100% cotton. Usually it can be checked by holding the cotton paper up to the light and looking just below the watermark for a number. 100% Cotton paper may contain small amounts of acids and should be tested or certified before use for archival documents.

Second-cut cotton linters have a normal average fibre length of 1.45 µm and have similar properties as a short softwood pulp.^[3]

Uses

Cotton paper is used in banknotes. Modern banknotes are typically made from 100% cotton paper, but can also be made from a mixture of 75% or less flax.^[4] Other materials may also be used and still be known as Currency paper.

Cotton bond paper can be found at most stores that sell stationery and other office products. Though most cotton paper contains a watermark, it is not necessary for it to have one.

Higher quality art papers are often made from cotton.

History

See also: history of paper, pulp (paper), and Deinking

Cotton was first used with a mixture of silk to make paper called carta bombycina. In the 1800s, fiber crops such as linen fibres or cotton from used cloths (rags) were the primary material source. By the turn of the 20th century most of the paper was made from wood pulp, but cotton is still used in speciality papers. As cotton rags now often contain synthetic fibres, papermakers have turned to second-cut cotton linters as raw material sources for making pulp for cotton papers.^[5]

References

1. ^ "What is 100% Cotton Bond Paper?". George Mason University. http://www.gmu.edu/library/specialcollections/dtcottonpaper.html. Retrieved 2009-02-07. ^{[dead link]}
2. ^ Southworth Paper Co
3. ^ Nanko, Hirko; Button, Allan; Hillman, Dave (2005). The World of Market Pulp. Appleton, WI, USA: WOMP, LLC. p. 62. ISBN 0-615-13013-5. 
4. ^ "Banknotes design and production". Bank of Canada. http://www.bankofcanada.ca/en/banknotes/facts.html. Retrieved 2009-02-07. 
5. ^ Nanko, Hirko; Button, Allan; Hillman, Dave (2005). The World of Market Pulp. Appleton, WI, USA: WOMP, LLC. p. 254. ISBN 0-615-13013-5.