THIS IS FOR ONE SINGLE MAT WITH Acid Free Backing Boards and Self-Seal Crystal Clear Bags , Featuring a picture opening for a 12x18 inch photo, to fit in a 16x20 inch picture frame. Photo openings are beveled cut 0.5" smaller than the art size advertised to overlap the photo and help keep it securely in the frame. MADE TO DISPLAY a 12x18 Photo and fit in a standard 16 x 20 Picture Frame. Vibrant White with Black Core color Acid Free Picture Matting. Great replacement for damaged, dirty, or faded matting in your old frames. PREMIUM QUALITY: Our precut photo matboards are acid free & precision cut with a 45 degree bevel by machine for perfect corners and NO over-cuts every single time! PRECUT ACID-FREE, PROFESSIONALLY BEVEL CUT Matte Board. Custom Frame Shop and Archival Quality. All of our Precut Matboards are proudly MANUFACTURED IN THE USA.