Golden State Art, Pack of 50, Acid-Free 16 3/8 x 20 1/8 inches Crystal Clear Sleeves Storage Bags for 16x20 Photo Framing Mats Mattes Brand new, Pack of 50, 16 3/8x 20 1/8 inches clear Bags for 16x20 photo mats It fits 16x20 double mat with backing. Contains a Re-sealable Adhesive Strip below the opening of the bag.