From www.leather-dictionary.com - The Leather Dictionary
Chagrin is leather made from the back of horses, camels, donkey, mules and other animals. The main characteristic of this type of leather is the artificial grain. Chagrin leather is embossed by grains, which are pressed into the leather while it is still damp. Nowadays, embossing is made with metal tools.
Chagrin is used for bridle, sabre sheaths or book covers.
"Real Chagrin" refers to the finely granulated skin of sharks and the characteristic surface of stingray leather.