Mat Board Center, Premier Crescent Pack of 50 5x7 White Picture Mat for 4x6 Photos 50 pieces of 5x7 Picture Mattes for 4x6 Photos Premium High Quality Mattes 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).