Our acid-free White Linen Canvas matboards are 4-ply and feature a white core. With an overall size of 12x16, these mats with Oval openings fit perfectly into 12x16 frames and are bevel cut to showcase your 10x13 photos. Actual mat opening size is 9.5x12.5 inches so that it may safely and securely house your 10x13 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!