THIS IS FOR ONE SINGLE MAT WITH an Acid Free Backing Board and Self-Seal Crystal Clear Bag, Featuring a picture opening for a 12x18 inch photo, and a 18x24 inch overall size. Picture openings are cut 0.5" smaller than the photo 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 18x24 Picture Frame. 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 MATTE BOARD COLOR is a vibrant Black. All of our Precut Matboards are proudly MANUFACTURED IN THE USA.