Silk is a natural protein fibre which can be woven into textiles. The best-known type of silk is obtained from cocoons made by the larvae of the mulberry silk worm. The shimmering appearance for which silk is prized comes from the fibers' triangular prism-like structure which allows silk cloth to refract incoming light at different angles.
"Wild silks" are produced by caterpillars other than the mulberry silkworm and cannot be artificially cultivated. A variety of wild silks have been known and used in China, South Asia and Europe since early times, but the scale of production was always far smaller than that of cultivated silks. They differ from the domesticated varieties in color and texture, and cocoons gathered in the wild usually have been damaged by the emerging moth so the silk thread that makes up the cocoon has been torn into shorter lengths. Wild silks also tend to be more difficult to dye than silk from the cultivated silkworm.