It is 100% natural and unbleached.
It is everything cotton rope shouldn't be - which is why it is being manufactured exclusively for bird toys. It is short fibered and, therefore, pulls apart easily, which will minimize the risk of entanglement. If you pull on the fibers from the ends or shafts, you will get cotton puffs instead of long threads.
5/16" diameter and sold by the foot in a continuous length. Buy quantity of 5 = 5 feet. This is a a great size for small to large size birds! Great product.