natural textile f. from the hair of animals and the cocoon of the silkworm, oak silkworm, etc.; composed of high-molecular proteins. Is divided into four main groups: wool, hair, horsehair, and natural silk. Used to produce [[101068|yarn]], [[100812|thread]] and [[100977|felt]], and the textile fabrics which result from these. The most important a. f. processed in the textiles industry include [[101497|wool]] and [[101064|natural silk]].