Posted By:
Steve MurrayLooking forward to seeing the pic.
You can eliminate the bowing effect by taking a strip of lath (A lath is a thin, narrow strip of some straight-grained wood or other material, including metal or gypsum) maybe an inch or two greater than the width of the frame and wedging it diagonally across the back.
Alternatively you could make a title insert for the center describing the display.