Flat keycaps that come out sort-of nicely on a 3D printer.
I print these in PETG on a textured sheet at 0.1mm layer height. Bigger than that starts to affect the stem. It's pretty important to print them top-down, that way the nice texture from the bed ends up on top. The STLs are arranged that way already.
This work is licensed under CC BY-NC-SA 4.0. Although please contact me if there's something you want to do that this license doesn't allow.
(For clarity, I do not consider charging materials and postage to print this for someone within the community to be "commercial use" and thus perfectly acceptable!)