Catgut suture used on a kit, or fiddle). Misinterpretation of the word kit as referring to a young cat led to the use of the term catgut. Surgical gut is in fact made from the submucosa of sheep intestine or the serosa of bovine intestine and is approximately 90% collagen. Perhaps another possible explanation of the name is the combination of the words cattle and gut. B Braun Medical AG, a German Multi National company first industrialized catgut suture and Catgut is a brand registered with B Braun. Catgut Chrome (B Braun) suture is a variant treated with chromic acid salts. This
Catgut as withstanding high tension within low alto, tenor, and high-bass ranges. Many acoustic guitarists moved away from gut strings in the early 1900s when the C. F. Martin & Company introduced steel strings, which gave greater volume to the guitar. "The demand for steel came from ensemble players, who couldn't make themselves heard clearly without it." Within a few years the majority of Martin guitars were made with steel strings to accommodate the demand. After World War II, most classical and flamenco guitarists switched from catgut to the new nylon strings for their greater smoothness, durability, and stability of intonation.