Mat Board Center, Pack of 20 11x14 MIXED COLORS White Core Picture Mats for 8x10 Photos High Quality Set of 20 pieces of 11x14 White Core Picture Mats for 8x10 Photo The opening size is 7.5"x9.5" for 8x10 print. Color: Mixed color This item comes with the 20 pre-cut matboards. The mats are beveled cut with white core and 4-ply thick (about 1.4 mm or 1/16 inch).