TL;DR:
Clothespin with a hook.

The weather forecast predicted >>35°C (that's >95°F :-), so I bought a few meters of the cheapest, yet lightproof curtain fabric I could find and created these hooks for hanging them up.
After doing so, I found hundreds of other possibilities to use them...

The Clothespin Hook is compatible to the most (tm) commercially available clothespins, and well, you'll need one of those springs...

But instead of throwing away both wooden/plastics parts, please consider only printing the "...R.stl" file and resusing the existing one.
The remaining, unused part can be thrown in one of your children's rooms. A perfect opportunity to stir things up... m/