Foam Board, Polystyrene, 40 x 30, White Surface and Core, 10/CartonAdd dimension to your creativity these boards are ideal for creating artwork or completing school projects. Designed for durability, lightweight foam display boards feature a polystyrene "memory" core that expands back into shape after cutting for a consistent thickness from edge to edge. Each foam board features smooth surfaces that are perfect for pencils, markers, paints, adhesives and fabrics. Strong enough to resist crushing and denting.