Ply Plies are the layers pressed together to create a piece of paper. The more plies, the thicker the paper (think 2-ply facial tissue). In picture framing, ply applies primarily to mat boards.
Mat boards are available in 2-ply, 4-ply, 6-ply and 8-ply. With each larger number, the mat board is thicker, which means the white bevel (if the mat's core is white) on the inner edge will be deeper. |