Mat Board Center, Pack of 10, 11x14 BLACK COLORS Picture Mats for 8x10 Photos White Core Pack of 10 pieces of 11x14 Picture Mats for 8x10 Photo The opening size is 7.5"x9.5" for 8x10 print. Color: Black This item comes with the 10 pre-cut matboards. The mats are beveled cut and 4-ply thick (about 1.4 mm or 1/16 inch).