Canvas Supplier is a closely woven, heavy cloth of cotton, hemp, or linen. Canvas these days are usually made of cotton or linen, although historically it is made mostly from hemp. Canvas differs from other heavy cotton fabrics, such as denim and drill cloth, in being plain weave rather than twill weave. Canvas comes in two basic types: plain and duck. The threads on duck canvas are more tightly woven. Canvas is classified in two ways: by weight and by a graded number system. The numbers run in reverse of the weight so a number 2 canvas is heavier than number 9.