MAT SIZE: This matting fits a 16x22 frame. (frame not included) * OPENING SIZE: This mat fits a 12x18 photo / print. (Actual opening size is 11.5x17.5) * Matting Material is Crescent Mat Board. * White Finish / Cream Core with White Backing (PH Neutral). * This listing includes (1) Custom Cut Mat. (The size selected represents the OUTSIDE dimensions of the matting.)