In this day and age we tend to think of parchment simply as paper, but it actually is a thin, paper-like material made from hide — i.e., goat-, sheep- or calfskin — and extra fine parchment is referred to as vellum. Different from leather in that it is not tanned but limed, parchment is not waterproof and reacts to humidity. Before paper was commonly available, parchment was used as a writing surface for manuscripts, documents and books, and it is still used today for book restoration, as well as on high-end furniture pieces and accessories.