Set of (30) 8x10 8-ply Black Mat for 5x7 Photo w/ Backing + Bag Set of (30) 8x10 8-ply BLACK mat for 5x7 photo w/ Back + bag This item comes with 30 single mats, 30 backing, and 30 bags The opening size is 4.5"x6.5" for 5x7 print. The mats are beveled cut with white core and 4-ply thick (about 1.4 mm or 1/16 inch).