This photo frames fold flat to mail and then has a pop-up stand for the recipient to display. It holds a 4"x 6" photo and fit within a 5" x 7" envelope for mailing. The file is compatible with the 12x12 and 8-1/2x12 mats. This frame can be used with horizontal or vertical photos. You can find a full tutorial and additional images on my blog: http://jamielanedesigns.blogspot.com/2013/08/mailable-4x6-photo-frames.html