This acid-free mat board features an attached backing board, pre-glued on three sides with one side left open to allow you to easily slip the print in place. The inside opening of the mat will be cut 1/2" smaller than the size ordered, a 1/4" overlay on either side of your artwork. The mat board, made with Crescent Select 4-ply mat, is available in black and white, as well as with and without a V-groove.