Mitre box (miter box) for 22mm fly screen (window screen)

Designed for 9mm thick fly screen, but if you're using thicker frame scal it  up vertically in the slicer. You want it to be 15mm taller in the slicer than the depth of the fly screen.  (eg, if your fly  screen is 16mm thick, scale it up to 31mm tall).

I guess you could scale it up or down in all directions to use with smaller/bigger frames (eg scale up to 113.6% for 25mm frame)

Screw down to a surface for extra stability