Parchment is the skin of sheep, ewes or lambs, cleaned, polished, stretched, and dried to make a material which can be written on, and also used to make drums and for bookbinding. Invented in the 2nd century BC as a substitute for papyrus, it was widely used for manuscripts until superceded by paper in the fifteenth century, except for legal documents. Velum is fine-quality parchment made from lamb, kid, or calf skin. Both terms are now applied to high-quality paper. Vegetable parchment is paper immersed briefly in sulfuric acid and so made strong and parchment-like.