Mat Board Center Premier Crescent Acid-Free Pre-Cut 5x7 White Picture Mat Sets. Includes a Pack of 50 White Core Bevel Cut Matte for 4x6 Photos, Pack of 50 Backers & 50 Clear Bags Set of 50 pieces of 5x7 Picture Mattes for 4x6 Photos with 50 backing boards and 50 crystal clear sleeve folding flap bags. Premium High Quality Mattes, Backers & Plastic Sleeve's that are all Made in the USA by Crescent. The opening size is 3.5"x5.5" for 4x6 photo prints. Color: White 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 sides. The re-sealable adhesive strip of the clear bag is below the opening of the bag instead of on the flap.