Lineco Acid-Free Book Binders Board, 70 Pt, 15 X 20.5 inches, Grey/Tan, Pack of 4 (473-4070)" /> This board is strong and acid-free and made from dense single ply board Perfect for constructing -book covers -boxes -slipcases This board is made to provide stability while resisting warping Grey and Tan in color -15 by 20.5 inches - .07 inch thick- comes in a 4 pack