Golden State Art, Acid free, Pack of 50 11x14 Black Picture Mats Mattes with White Core Bevel Cut for 8x10 Photo + Backing + Bags Set of 50, 11x14 Picture Mats for 8x10 Photo with backing boards and bags Set includes 50 pre-cut mats, 50 backing boards and 50 clear bags. The mat opening size is 7.5"x9.5" for 8x10 print. Color: Black The mats are beveled cut with white core and 4-ply thick (about 1.4 mm or 1/16 inch). The backing board is white on both sides. The re-sealable adhesive strip of the clear bag is below the opening of the bag instead of on the flap.