vellum
noun [ U ] uk/ˈvel.əm/ us/ˈvel.əm/
（用于书写的）仿犊皮纸，仿羊皮纸
a thick, cream-coloured, very high-quality writing paper
（旧时的）犊皮纸，羊皮纸
a material used in the past for writing on or for covering a book, made from the skins of young animals, especially cows or sheep