This little card fits in your wallet and allows you to quickly identify common screw sizes and lengths in both Imperial and Metric! These are great to have around and easy to give to friends or coworkers. This is a free download for the 3D printing file (a .stl file.) It also works as a weird little comb if you’re in a pinch.
For optimal results, print with .3mm layer height and a smaller nozzle (.4mm pictured, which is ~mostly readable!) I recommend turning on “ironing” for the top layer to make the top and bottom surfaces smooth. I also recommend using a contrasting color for the middle layer to make the text easier to read.