10-Mats w/ Backings & Clear Bags You will receive 10 Individual Mats, Backings and Bags. Acid Free, White Core 4-Ply Mats Overall Size 6" x 7.5" - Bevel Cut Opening Size of 2.5" x 4.5" for 3" x 5" Photo Backing and Clear Bags ARE included with this option. Our Acid-Free matboards are 4-ply and feature a White Core. With an overall size of 6" x 7.5", these mats with oval openings fit perfectly into 6" x 7.5" frames and are bevel cut to enhance your 3" x 5" photos. Actual mat opening size is 2.5" x 4.5" inches so that it may safely and securely house your 3" x 5" photo, artwork, needlepoint, sign, etc.