Purified cotton linters usually in the form of standard sheets about 1 mm thick.
Note:The preparation of the linters involves one or more pressure boils with sodium hydroxide (caustic soda) followed by hypochlorite bleaching, the severity and number of the boils depending on the use to which the resultant material is to be put. The fibres are composed of glucose units to the exclusion of other sugars and only 1-2% of the cellulose is soluble in sodium hydroxide (caustic soda) of 17.5% strength at 20°C. Suitability for a specific purpose is determined by measurement of the viscosity of the product under standard conditions, and different viscosity ranges are usually specified for material to be used for man-made fibres, lacquers, etc. The material is also supplied in pressed bales
Textile Resource (http://www.textile.org.uk)