CHARTPAK Vellum Pad, 50 Sheets, Acid-free, 11"x17", White - Vellum pad contains 50 sheets of 16 lb. vellum paper made with 100 percent cotton fiber. Unprinted paper is treated with high-impact oil resins to produce a permanently transparent drawing surface. Smooth white surface is suitable for pencil and ink. Acid-free, archival vellum pad is produced without solvents to meet EPA requirements. 16 lb.