Our acid-free Charcoal matboards are 4-ply and feature a white core. With an overall size of 27x27, these mats with Square openings fit perfectly into 27x27 frames and are bevel cut to showcase your 22x22 photos. Actual mat opening size is 21.5x21.5 inches so that it may safely and securely house your 22x22 photo, artwork, needlepoint, sign, etc. This pack includes 1 Single Matboard. Proudly made in the USA by Country Art House!