Pig casings belong to the food field and are used to fill sausages for everyone to eat, so companies exporting casings processing must comply with the rules of the "Code for the Registration of Export Casings Processing Companies" issued by the State Commodity Inspection Bureau to make their processing and cleaning conditions meet the requirements. The materials selected for processing should come from safe non-epidemic areas and be inspected by veterinarians before and after slaughter for healthy and disease-free livestock.

High-quality pig casings should be thin and clear, no damage, no peculiar smell, and meet the national standard or customer requirements after measurement and grading. There are several colors of high-quality casings: white, milky white, light pink, yellow-white, off-white.

Pig casing refers to the small intestine through processing and scraping a clear film, and tearing the mesh-like, very fine fibers by hand. This kind of fiber is a protein fiber, because its composition is a network of canine teeth interlaced, so its longitudinal pull, transverse tension are strong, it is a thin coating film outside the sausage or sausage, suitable for both craft enema and machine filling. Sausages filled with pig casings are not dyed, and the filling of the sausage can be seen with the naked eye, giving a clean feeling and increasing appetite.