Check the listing for details. 25-pack of Crystal-Clear Comic Clear Backing Boards - Silver Age Size. Listed at 29.99 USD. 25 crystal clear Silver Age sized backing boards per pack. Comic Clear backing boards are made of 100% archival, acid-free and completely transparent PET plastic. They will not discolor over time or absorb off-gassing from comics as they age. This makes them the only backing board that doesn't need to be changed out every 3-5 years. Each board is covered on both sides with an easy-to-remove film that ensures every board is free of scratches and scuffs. Comic Clear Silver Age boards fit comics made between approximately 1956 and 1970. Sized slightly wider than Silver Age comic books, these boards provide an extra margin of protection on all sides. Fit all major brands of Silver Age sized comic bags. Quantity: 25 boards/packDimensions: 7" x 10.5"Thickness: 0.8mmMaterial: archival, acid-free plasticEasy-to-remove protective film ensures boards remain scratch and scuff-free