Print 

These terms are used with bristol board, but not illustration board. A plate surface is roughly equivalent to hot press, while a vellum surface is roughly equivalent to cold press. Bristol Smooth has a flat, smooth surface and is great for pen & ink, mechanical pencil, airbrush, and marker. Bristol Vellum has a medium surface with peaks and valleys, making it great for graphite, colored pencil, charcoal, pastel, and crayons.