information:highlighting
Vellum is prepared animal skin or membrane, typically used as writing material. It is often distinguished from parchment, either by being made from calfskin, or simply by being of a higher quality. Vellum is prepared for writing and printing on single pages, scrolls, and codices (books). Modern scholars and experts often prefer to use the broader term "membrane", which avoids the need to draw a distinction between vellum and parchment. It may be very hard to determine the animal species involved without detailed scientific analysis. Vellum is generally smooth and durable, but there are great variations in its texture which are affected by the way it is made and the quality of the skin. The making involves the cleaning, bleaching, stretching on a frame, and scraping of the skin with a crescent-shaped knife. To create tension, the process goes back and forth between scraping, wetting and drying. Scratching the surface with pumice, and treating with lime or chalk to make it suitable for writing or printing ink can create a final look. Modern "paper vellum" is made of plant cellulose fibers and gets its name from its similar usage to actual vellum, as well as its high quality. It is used for a variety of purposes including tracing, technical drawings, plans and blueprints. Tracing paper is essentially the same thing, however the quality level differs, sometimes greatly.