Strathmore 500 Series Sequential Art Bristol Sheets - 100% cotton, acid-free 100 lb. paper formatted for sequential art. Plate Surface has an ultra-smooth finish that is unsurpassed for detail work using traditional pen and ink tools, specialty pens, specialty markers and airbrush. Vellum Surface has a toothy finish that is excellent for graphite pencil, colored pencil, sketching sticks and specialty pens and markers. It is also very good for charcoal, pen and ink, airbrush and light washes. Not recommended for traditional watercolor techniques. Semi-smooth Surface is slightly textured and suited for pen and ink tools, pencil and specialty pens and markers. Twenty-four 2-ply sheets per package.