Mat Board Center, Pack of 20, 8x10 MIXED COLORS White Core Picture Mats Mattes Matting for 5x7 Photo Pack of 20 pieces of 8x10 White Core Picture Mats for 5x7 Photo The opening size is 4.5"x6.5" for 5x7 print. Color: Mixed color This item comes with the 20 pre-cut mats. The mats are beveled cut with white core and 4-ply thick (about 1.4 mm or 1/16 inch)