This economical heavyweight (100 lb.) paper is acid-free and available in a choice of two surfaces: smooth and vellum. Smooth is ideal for fine pen & ink, pencil, and mechanical drawing. Vellum has a slight "tooth" and is designed for a broad range of drawing and painting media including crayon, pencil, charcoal, watercolor, and gouache. Both surfaces are ideal for airbrush. 20 sheets per pad.