Parchment
2 of the 7 encyclopedias on this shelf carry an entry for Parchment. Both are reproduced below, so you can see where they agree and where they differ.
Aiton's Encyclopedia (1910)
the skin of a sheep or goat prepared for use as writing material. The name is a corruption of Pergamus, a city of Asia Minor noted for its manufacture. After the Saracens occupied Egypt and cut off the world's supply of papyrus, Pergamus drove an immense business in tanning skins as a substitute for papyrus. In the making of parchment the skins are first soaked in lime to remove the hair. They are then scraped, shaved, washed, stretched, and dried. The surface is rendered smooth and hard by rubbing with fine chalk and pumice stone. Parchment is still in demand for documents of importance, diplomas, bindings, and trimmings. A wolf-skin parchment makes the best drumheads. Vellum is a fine parchment made of the skin of a kid or a young calf. The Eskimos make a kind of parchment from the entrails of seals. They use it for bags, boots, robe linings, and the like. Owing to the expense of parchment the medieval monks were wont to fade the ink of old volumes and use the parchment again. A second-hand roll of this sort was known as a palimpsest. See Papyrus ; Paper ; Book ; Tanning
Collier's New Encyclopedia (1921)
the skin of a very young calf, sheep, or goat, dressed and prepared for writing on, etc. After removing the wool, the skin is steeped in lime and stretched in a wooden frame, and its face is scraped with a half-round knife. The skin, previously sprinkled with powdered chalk or slacked lime, is then rubbed and scraped with a knife, and it is then rubbed with a lambskin having the wool on to smooth the surface and raise a very fine nap. The grain surface is then removed with a knife and the skin pumiced, if necessary, to give it an equal thickness. Extra fine, thin parchments are made from the skins of still-born lambs, kids, and calves. Coarse parchment for drumheads, etc., is made from calves', asses', and hegoats' skins.