Pack of 50 8x10 White Picture Mats Mattes with White Core Bevel Cut for 5x7 Photo + Backing + Bags This item comes with 50 single white mats, 50 backing, and 50 bags. The opening size is 4.5"x6.5" for 5x7 print. Color: White The mats are beveled cut with white core and 4-ply thick (about 1.4 mm or 1/16 inch). The re-sealable adhesive strip of the clear bag is below the opening of the bag instead of on the flap. The re-sealable adhesive strip of the clear bag is below the opening of the bag instead of on the flap. Our acid-free whitecore matboards are a 4-ply papermat that provide the aesthetic and design benefits of a bright white bevel., Each sheet of mat board has a richly colored front surface, a white core and a white backing. It can be used for matting photos, art, and needlepoint. Also great for crafts, backboards, signs, children's projects, and school projects.