Foam Board features a resilient polystyrene core that "bounces back" after handling, cutting or mounting. Strong yet lightweight, rigid yet versatile. Its paper surface has a double-clay coating that yields an ultra-smooth finish. Elmer's Foam Board assures you a quality performance no matter how you use it. CFC-free. Peel off the backing sheet of this self-adhesive, white foam board to permanently mount posters, artwork and more! 20x30 sheets measure 3/16" thick. Available in cases of 25 sheets only.