Which fabric absorbs the most water; cotton or polyester?

Shorter answer: Cotton will absorb more water because it is a natural & porous cellulose. Polyester will not absorb any water because it is a manmade plastic. Longer answer: Polyester is a plastic that is extruded into fine fibers which are then spun into yarn & woven/knit to create fabric. The tiniest little thread you see in any yarn or fabric is the fiber. Polyesters are not only used to make fabric but are also used to produce many items such as bottles and finishes on wooden products like guitars and pianos. Since polyester is a plastic the fiber itself will not absorb water (also known as hydrophobic, it hates water). Water can, however, become trapped in between the fibers that make up the yarn. For example, think of a fluffy polyester yarn that is used for knitting. The yarn can get wet but that is because the water is actually trapped in between all of the tiny fibers that make up the fluffy yarn, not inside of the fiber itself. Cotton, is a natural plant fiber which is ...  more