For the 8x10 mat, the opening size is 4.5"x6.5" for 5x7 print.

For the 11x14 mat, the opening size is 7.5"x9.5" for 8x10 print.

For the 16x20 mat, the opening size is 10.5"x13.5" for 11x14 print.

The mats are cut at beveled.

The backing is also 4-ply.

The re-sealable adhesive strip of the clear bag is below the opening of the bag instead of on the flap.

 Our acid-free whitecore matboards are a 4-ply papermat that provide the aesthetic and design benefits of a bright white bevel., Each sheet of mat board has a richly colored front surface, a white core and a white backing. It can be used for matting photos, art, and needlepoint. Also great for crafts, backboards, signs, children's projects, and school projects.