Polystyrene extruded foam laminated between 2 sheets of paper that feature a faint ½" grid 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. Sheet size is 22" x 28". Sold by the carton. (Carton contains 25 sheets)