This painting has a single mat of sage green. Each painting is an original and you are selecting the actual one you will be receiving. This painting is rectangular, even if my photograph doesn’t make it look that way. Some of the mat may have been cropped from the picture. Exterior dimensions are 19.5" x 15.5". Cut-out for the painting is 14" x 10". It could be rematted to a 16 x 20 mat. Finished dimensions depend on the size of the frame you purchase for it.