According to the classification of livestock, it can be divided into pig casings, sheep casings and cattle casings, and can also be divided into small casings and large casings. In addition to sausage and enema, casing can also be made into catgut, which is used to make tennis racket strings, bow strings, musical instrument strings and surgical sutures.

China has been processing casings for more than 100 years, and pig casings are mostly produced in East China and Central China. Sheep casings are mostly produced in North China, Northeast China, Inner Mongolia and other places. Originally only used for bowstring and elastic cotton thread, the output is limited. In the early 20th century, factories were set up in Tianjin, Beijing and other places for processing and production, which soon became an important export material of China.