The silkworm is found in some medieval encyclopedias. It weaves webs like spiders, producing a luxurious cloth for women's dresses, called silk. The larva of various insects were said to produce "wool" that was spun into silk, not just the silkworm (bombyx). The basic methods of silk production were known the the writers of medieval encyclopedias in the thirteenth century.

The best silk came from China, where the method of its production was a closely guarded secret. Silkworm eggs, along with the secret of silk production, were smuggled to Byzantium around 550 CE and some silk was produced there, but not in great enough quantities (or quality) to meet demand. Silk production started in Spain by around the ninth or tenth century, and in Italy in the thirteenth century, though neither could supply enough to satisfy the demand for silk cloth, which continued to be imported from China via the Silk Road.