Although there is extensive practical knowledge of cotton processing, a more thorough

understanding of cotton fiber structure will improve exploitation of today’s fiber. Still, the

ultimate reason to seek such understanding is to be able, through genetics, biochemistry, or

chemistry, to tailor fiber to have new or improved properties. The initial structure of a cotton

fiber is determined by biosynthesis, a series of processes that are subject to substantial

influence during fiber growth. After the boll opens, there are many factors that affect the

structure, from the weather before the fiber is harvested to the industrial processes such as

mercerization. Cotton fibers are composed mostly (e.g., 95%) of the long-chain carbohydrate

molecule, the cellulose (the sugar of cell walls). In this overview and Section 5.2 through

Section 5.5, we are concerned with the physical structure of cellulose and the fibers, as

revealed by various methods.