Golden State Art, Acid-free Pre-cut 8x10 Black Picture Mat Sets. Includes Pack of 100 White Core Bevel Cut Mats for 5x7 Photos, 100 Backing Boards and 100 Crystal Clear Plastic Sleeves Bags Set of 100 8x10 White Core Picture Frame Mats with Backing Boards and Crystal Clear Bags. Opening Size is 4.5" x 6.5" for 5x7 inch pictures. Color: Black The mats are beveled cut and are 4-ply thick (1.4mm or 1/16 inch) All products in this kit are acid free, perfect for use in hobbies or art gallery exhibits. Note: Please Unwrap the plastic wrap & Flip the first mat over to see the actual color mat.