Cleaning - boiled in caustic soda and bleached. Mercerization - stretched and placed in cold caustic soda, increases luster, dye upstake and durability. Sizing - stiffening agent before weaving. Sanforization - use of ammonia process that swells fibers and prevents shrinking. Permanent press - chemicals used to crosslink polymers.
Fibers come from thick fibrous mesocarp.
Best coir comes from immature coconuts, which are retted, washed and beaten. This conflicts with harvesting of coconuts for food or oil, so most coir comes from mature fruits. Fibers are used as mattress stuffing, bristles in brooms and brushes. Easily grown and processed. Flax industry never became mechanized since mechanically processed flax is not as good as that produced by hand, so linen is expensive.