The opening size is 7.5"x11.5" for 8x12 print.
The mats are bevel cut.
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.