Bristol pads feature 100lb (270gsm) extra-white, acid-free in smooth or vellum surfaces. The smooth texture has a silky finish, ideal for detail, technical drawing and intricate work. The vellum has a medium texture and is ideal for illustration work. Use with pencil, charcoal, soft and oil pastel, pen, pen & ink, marker, and airbrush. Erases cleanly. Available in glue-bound with fold over.