If you have a towel hook on your wall, but the towels you own have no loop, this screw-on hanger is a simple solution that requires no sewing or extra parts. This solution is great for a towel next to a washing basin because you can just keep the towel on its hook while using it.

The model can simply be printed from PLA. Note that the tolerance of the screw mechanism is very low. Screwing the halves together for the first time may require some force.