cuir bouilli

noun1

1. •
   Leather treated so as to become tough and rigid (and able to hold a moulded shape and decoration), used for artwork, carrying cases, and armor.

   • Cuir-bouilli was leather softened by boiling (generally in oil), and stamped or moulded into a definite form when in that condition; upon drying it became intensely hard and tough. — 1909