Pack of 100 sets, 5x7 White Picture Mats with White Core for 4x6 Photos + Backings+ Bags Pack of 100 sets, 5x7 White Picture Mats with White Core for 4x6 Photos + Backings+ Bags This item comes with 100 single mats, 100 backing boards and 100 clear bags. The opening size is 3.5"x5.5" for 4x6 print. Color: WHITE The mats are beveled cut with white core and 4-ply thick (about 1.4 mm or 1/16 inch). The re-sealable adhesive strip of the clear bag is below the opening of the bag instead of on the flap.