Silk: Silk is a natural protein fibre. The protein fibre of silk is composed mainly of fibroin and produced by certain insect larvae to form cocoons.The best-known type of silk is obtained from the cocoons of the larvae of the mulberry silkworm Bombyx mori reared in captivity (sericulture). The shimmering appearance of silk is due to the triangular prism-like structure of the silk fibre, which allows silk cloth to refract incoming light at different angles, thus producing different colors. Silk is one of the strongest natural fibers but loses up to 20% of its strength when wet.
Wool: Is the textile fiber obtained from sheep and certain other animals. Wool has several qualities that distinguish it from hair or fur: it is crimped, it is elastic, and it grows in staples (clusters). Because of the crimp, wool fabrics have greater bulk than other textiles, and they hold air, which causes the fabric to retain heat.