In the early years pig’s bladder was used as the ball. However, today’s football is an inflated rubber bladder or cowhide. This material is extremely durable as well as easily tanned. After the tanning process, the cowhide is cut into a bend which is the strongest part of the hide. Rubber is used from latex on a tree or polyurethane made from the reaction of a polyol (an alcohol containing multiple hydroxl groups) with a diisocyanate or isocyante, (a compound used to make resin and plastic). Paint made from pigment resin, solvent and string vinyl is also used, as well as cotton, polyester, hemp, nylon or linen and lastly.
An example of how the materials a football was made out of prior to the modern change to leather.