Catgut

Catgut (also known as gut) is a type of cord[1] that is prepared from the natural fiber found in the walls of animal intestines.

[5] In the 16th century a "kit" was a "small fiddle used by dancing teachers," a name probably derived from a shortening of Old English cythere, from Latin cithara, from Greek kithara (see guitar).

Most musical instruments produced today use strings with cores made of other materials, generally steel or synthetic polymer.

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.

To prepare catgut, workers clean the small intestines, free them from any fat, and steep them in water.

After drying and polishing, workers bleach and disinfect the strings using sulfur dioxide, dye them if necessary, and sort them into sizes.

Catgut sutures are normally treated with a chromium salt solution to resist body enzymes to slow the absorption process.