Craig Frames 16x20 White Mat with Cream Core and 12x16 Opening Size (B222MAT) This listing includes (1) Custom Cut Mat OPENING SIZE: This mat fits a 12x16 photo / print. (Actual opening size is 11.5x15.5) MAT SIZE: This matting fits a 16x20 frame. (frame not included) White Finish / Cream Core with White Backing (pH Neutral). Matting Material is Crescent Mat Board.