Polystyrene extruded foam laminated between two sheets of paper to form a lightweight but strong and rigid surface. Ideal for crafts, school projects, framing, mounting, displays, posters and exhibits. Easy-to-cut sheets have a smooth surface, and accept a wide range of media including paints. Sheets are 3/16" thick. Acid free. includes five sheets of White, plus one sheet each of Black, Blue, Green, Red and Yellow.