n.上等皮纸；精制皮纸
Vellum is a thick tracing paper stock, good for line drawing. 是厚的描图纸，尤其方便用在针笔线图上。
Vellum paper with a glazed surface is used for decorative documents. 有光泽的仿牛皮纸，是精美文件用纸。
