One Single Mat With Acid Free Backing Boards And Crystal Clear Self Seal Bag, Featuring A Picture Opening For A 11X17 Inch Photo, To Fit In A 12X18 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 11X17 Photo And Fit In A Standard 12X18 Picture Frame. Vibrant Black 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.