Two-piece platform for digitizing 135 film (35mm) with DSLR.
I enlarged the holes slightly with a drill after printing to make it easier to assemble the parts. I also double-stick taped microfiber cloth pads to each half so when assembled, the film is gently sandwiched between the pads. (Helps to keep it flat, and avoids scratching).
Photo shows setup with a larger variation of the same platform.