Mats are formed by cutting a piece of mat the size of the frame and then cutting a window in the mat to outline the picture. When you purchase a full sheet of mat board it is a good idea to cut some standard sizes to have them on hand for framing projects. The most common things we want to frame are photos, post cards, and diplomas which all come in standard sizes. Lets try and match the standard sizes of things we want to frame with the standard frames sizes. The strange reality is that they don't agree well. In the chart below, the columns correspond to sizes of things to frame. The rows correspond to standard frame sizes. The numbers in the table are the resulting boarder widths. The standard frame sizes are 8x10 and 11x14. The highlighted entries correspond to the best picture and frame combinations.