My V550 didn't come with film holders, and I wasn't 100% happy with the currently available 3D models, so I made my own. Main thing this holder does different is it has little posts to hold the film in a set position, so I don't have to constantly re position the frame guides in my scanning software (SilverFast, you can get it for free if you own an Epson).

Uses 6x1.5mm disc magnets.

0.2mm or another multiple of 1mm layer height recommended. (Ordered and returned a replacement film holder to get exact height measurements, and it sits 1mm above glass) Would recommend leaving print on the plate until it's cool so that you don't warp the guides.