Pack of 100 sets of 5x7 MIXED COLORS Picture Mats Mattes Matting for 4x6 Photo + Backing + Bags Set of 100 pieces of 5x7 Picture Mats with white core bevel pre-cut for 4x6 Photo with backing boards and bags This item comes with the 100 pre-cut mats, 100 backing boards and 100 clear re-sealable bags. These are Acid Free matboards, Standard 4 ply: 1.4 mil or 1/16 inch. The backing is white on both side. Outside Dimensions: 5x7", Inside Dimensions: 3.5x5.5" bevel cut (to fit 4x6 photo) Perfect for framing 4x6 photos in an 5x7 picture frame.