Quickly calculate mat borders without doing the math!   Often with mats the top and bottom borders are  different than the side borders.  The Fit-N-Frame takes all this into account and allows you to fit any size frame.  Measure the artwork with the Fit-N-Frame, then transfer the settings over to the mat size necessary to fit your frame.  Simply align the triangles on your artwork and then transfer them,  The scaled border grid shows you what size borders your mats need.  A great tool for anyone who struggles with measuring for framing.