Photo Light Box Corners

These corners fit 5mm foam board. I've included the .f3d file for alterations if your board is larger or smaller. 

If your boards are rectangles and you dont want to cut the excess off for the front tabs you can sink them on the build plate until the face is open. I included a .3mf file showing open face brackets for the front corners.

I printed these with a .6mm nozzle, 5% infill, 3 top/bottom layers, and I used PETG but you could use PLA and be fine.