Our acid-free Charcoal matboards are 4-ply and feature a white core. With an overall size of 9x11, these mats with Oval openings fit perfectly into 9x11 frames and are bevel cut to showcase your 5.5x8.5 photos. Actual mat opening size is 5x8 inches so that it may safely and securely house your 5.5x8.5 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!