The method was frequently modified until now it is capable of producing the finest diameter of any of the rayons. 1. Cotton linters afford the greatest purity and are the preferred source cellulose. These fibers are cleansed by cooking in a mild caustic alkali and bleached with chlorine.

Resistance to acids : Good Resistance to alkalies : Low; many alkalies destroy the fiber. Sunlight : Prolonged exposure deteriorates fiber Insects : Damaged by moths and carpet Beetles. To flame : Burns slowly when in direct flame, is considered to be self extinguishing.