Calfskin

Calfskin is a leather or membrane produced from the hide of a calf. Calfskin is particularly valuable because of its softness, and fine grain. It is commonly used for high-quality shoes, wallets and similar products, as well as traditional leather bookbindings. Fine calfskin is one of the skins used for vellum and parchment manuscripts.

See also

Goldbeater's skin, made from the intestine of a calf
Sheepskin (material)