Catgut down to the desired diameter using a centerless grinder. 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, and are called catgut chromic sutures—whereas untreated catgut sutures are called catgut plain sutures. Catgut Catgut is a type of cord that is prepared from the natural fibre found in the walls of animal intestines. Catgut makers usually use sheep or goat intestines, but occasionally use the intestines of cattle,
Strings (tennis) contemporary string material. It is usually added to nylon string to increase nylon's durability and stiffness, as with Kevlar. Yonex, for instance, offers two badminton strings, made primarily from nylon, which have Vectran strands. However, the Ashaway company offers a braided Vectran tennis string. Zyex string offers more rebound efficiency, i.e. gut-like dynamic stiffness, than other synthetic strings, particularly when strung at low tensions. This gives it playability that is more similar to natural gut than, arguably, other synthetic materials. It also has low overall stiffness. The ProKennex IQ Element Z string, for instance, has the lowest stiffness of any