Golden State Art, Pack of 25 White Pre-Cut 5x7 Picture Mat for 4x6 Photo with White Core Bevel Cut Mattes Sets. Includes 25 High Premier Acid Free Bevel Cut Matts & 25 Backing Board & 25 Clear Bags Pack of 25 5x7 White Picture Mats Mattes with White Core Bevel Cut for 4x6 Photo + Backing + Bags This item comes with 25 single white mats, 25 backing, and 25 bags. Mat Opening size is 3.5" x 5.5" inches for 4x6 Pictures. The mats are beveled cut with white core and 4-ply thick (about 1.4 mm or 1/16 inch). The backing board is white on both sides and core is brown. The re-sealable adhesive strip of the clear bag is below the opening of the bag instead of on the flap.