Our acid-free Royal Blue matboards are 4-ply and feature a white core. With an overall size of 8x8, these mats with Square openings fit perfectly into 8x8 frames and are bevel cut to showcase your 4x4 photos. Actual mat opening size is 3.5x3.5 inches so that it may safely and securely house your 4x4 photo, artwork, needlepoint, sign, etc. This pack includes 1 Single Matboard. Proudly made in the USA by Country Art House!