Catgut suture treatment produces roughly twice the stitch-holding time of plain catgut, but greater tissue inflammation occurs. Full tensile strength is extended to 18–21 days. It is brown rather than straw-colored, and has improved smoothness due to the dry presentation of the thread (plain catgut is wet). It is otherwise similar to plain catgut. Fast catgut suture is heat-treated to give even more rapid absorption in the body. The first known absorbable sutures were made of the intestines of sheep. The manufacturing process was similar to that of natural musical strings for violins and guitar, and also of natural strings for tennis
Classical guitar strings Classical guitar strings Classical guitar strings are strings manufactured for use on classical guitars. While steel-string acoustic guitar strings and electric guitar strings are made of metal, modern classical guitar strings are made of nylon and nylon wound with wire, which produces a different sound to the metal strings. Classical guitar strings were originally made with animal intestine and silk wound with animal intestine up until World War II, when war restrictions led Albert Augustine Ltd. to develop nylon strings. Nylon guitar strings were put into production in 1948. Strings made from fluorocarbon polymers have since been developed and are