Golden State Art, Pack of 50 8x10 BLACK Picture Mat Mattes with White Core Bevel Cut for 5x7 Photo + Backing + Bags This set comes with the 50 pre-cut 8x10 mats, 50 backing boards and 50 clear bags. The 8x10 mat opening size is 4.5"x6.5" for 5x7 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 is white on both side. Please Unwrap the plastic wrap & Flip the first mat over to see the actual color mat. The re-sealable adhesive strip of the clear bag is below the opening of the bag instead of on the flap.