Wool fabric is made from the natural fibers that form the fleece of animals such as sheep, goats, rabbits, camels, and more. This raw material is primarily made up of keratin-based proteins, which makes wool a remarkably elastic material. After cotton and synthetic fibers, wool is one of the most common textiles in the world. The biggest appeal of wool garments is that they hold in heat extremely well. Additional benefits of wool include its durability and its versatility, as it can be woven into both heavy, coarse fabrics and lightweight, soft fabrics.