Skin of a calf, treated so as to be suitable for writing on. Something like 120 animals were killed to provide sufficient skins to be turned into vellum for an illuminated *codex of the Bible. Skins of the 12c are often yellower than those of later dates as a weaker lime-water solution was used in the bleaching process. [< OldFr. vel = a calf]
Dictionary of Medieval Terms and Phrases. Christopher Coredon with Ann Williams.