Our 4-ply matboards are Acid-Free and feature a White Core. With a 11" x 14" overall size, these mats fit perfectly into 11" x 14" frames and are bevel cut to enhance your 8" x 12" photos. Actual mat opening size is 7.5" x 11.5" inches so that the mat may safely and securely house your 8" x 12" ph