That makes sense. I never thought of elastic-induced distortion. Instead of using rubber bands directly on my holders, I completely enclosed the back of my camera and slid the holders through a slot. I know the open back concept works, as in your camera and the Zero Image 4x5s, but I was thinking "multi-task" and wanted a box I could store a box or two of film in when I'm not shooting. Mine works for both purposes but is not nearly as good looking as your setup.