The skin of an animal (sheep, calf or goat) prepared for writing and/or painting. Parchment was used for the production of books in antiquity and the Middle Ages. The finer variety of parchment is called vellum. Web resource here. Video here.

Detail of parchment. Boethius, De institutione arithmetica. Ca. 1100 CE. Royal Library, The Hague, Netherlands. MS 78 E 59.