Our acid-free Forest Green matboards are 4-ply and feature a white core. With an overall size of 9x12, these mats with Oval openings fit perfectly into 9x12 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. Proudly made in the USA by Country Art House!