Strathmore 300 Series Bristol Pads contain heavy-weight 100lb, acid-free paper in a choice of two surfaces.
Smooth surface bristol paper is good for technical applications in mechanical drawing, marker, pen & ink and airbrush.
Vellum has a bit more texture to better accommodate graphite pencil, colored pencil, charcoal, mixed media and oil pastel.
Each tape-bound pad contains 20 sheets of 100 lb. paper. In sizes 9" x 12", 11" x 14", and 14" x 17".