Mat Board Center, Pack of 10 Premier Acid-Free Pre-Cut 16x20 White Picture Mats for 11x14 Photos Set of 10 pieces of 16x20 Picture Mattes for 11X14 Photos The opening size is 10.5 x 13.5" for 11x14 photo prints. Color: White The mats are beveled cut with white core and 4-ply thick (about 1.4 mm or 1/16 inch). THIS ITEM DOESN'T INCLUDE BACKING BOARD AND CLEAR BAG.