11" x 17" 2-Ply 500 Series Tape Bound Sequential Art Bristol Vellum Paper - 24 Sheets:. This 100 percent cotton Bristol Vellum is an industry standard. It has been the choice among sequential art professionals and award winning illustrations for years. Semi-smooth is slightly textured. It is suited for pen and ink tools, pencil, specialty pens, and markers. It is also very good for charcoal, pen and ink, airbrush, and light washes. Not recommended for traditional watercolor techniques. 11" x 17". Pads and packs have 24-sheets. Acid-free. 2-ply.