Our acid-free Oyster Shell White matboards are 4-ply and feature a white core. With an overall size of 14x18, these mats with Oval openings fit perfectly into 14x18 frames and are bevel cut to showcase your 12x16 photos. Actual mat opening size is 11.5x15.5 inches so that it may safely and securely house your 12x16 photo, artwork, needlepoint, sign, etc. This pack includes 1 Single Matboard Show Kit With Acid Free Backing & Clear Bag. Proudly made in the USA by Country Art House!