Set of 50 pieces of 11x14 Picture Mattes for 8x10 Photos with 50 backing boards and 50 crystal clear sleeve folding flap bags. US Art Supply Brand Premium High Quality Mattes, Backers & Plastic Sleeve's that are all Made in the USA by Crescent. The opening size is 7.5"x9.5" for 8x10 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.