This is a simple and quick to print wall hook for a hanging a longboard to the wall. I used a 1/8 inch thick screw to mount it, which is a little under 4 mm for those using smart person units.
I printed it on the side, which gave it better strength but made the curves and the screw hole look a little sloppy. However I imagine that it would be strong enough if you print it with the wall side facing the bed, which would make the holes and the curves better. If you print it this way, you may have to increase the infill and up the parameters, but it should work fine.