Vellum is a type of parchment, which is an animal skin that was traditionally used as a writing material for important documents such as land records, religious texts and public laws. Parchment could be made from the hides of goats, calves or sheep. Vellum, however, referred specifically to a writing material made from calf skin.
Animal vellum is rarely used in the 21st century. During the late 1800s, a durable, translucent, slightly glossy paper was created that simulated the appearance of calf-skin vellum. This ivory-colored paper stock, which is made from cotton fibers and wood pulp, is available in two varieties. Bristol vellum, or vellum-surface bristol, is a thick variety that is commonly used for art media such as pastels, paint or ink. Drafting or design vellum is semi-transparent, which makes it useful for technical drawing.