Presentations and projects will be taken to a whole new level with foam core boards. The smooth, bold black surface has a matte finish that easily accepts markers, crayons, paints and adhesives. Lightweight and rigid, foam board cuts easily with a knife or razor. Perfect for mounting photographs and artwork, 3-D modeling, signage, poster making and more. Boards measure 20" x 30" with 3/16" (5mm) thick, dense deep grey polystyrene foam core and black on back of sheet.