Single Mat You will receive one single mat. Acid Free, White Core 4-Ply Mats Overall Size 20" x 20" - Bevel Cut Opening Size of 11.5" x 11.5" for 12" x 12" Photo Backing and Clear Bags are NOT included with this option. Our Acid-Free matboards are 4-ply and feature a White Core. With an overall size of 13" x 19", these mats fit perfectly into 13" x 19" frames. Each mat is bevel cut to enhance your 11" x 14" photos. The actual mat opening size is 10.5" x 13.5" inches so that it may safely and securely display your 11" x 14" photo, artwork, needlepoint, sign, etc.