This is a remix of a cubicle coat hook from bharris555 on Thingiverse with changes to fit my work cubicle walls. The walls have fabric with a metal top. I printed it solid in PLA + and it will hold a full backpack with no problem. You can use less infill and walls if you are just hanging a lightweight coat.

Print settings I used on Elegoo Centauri Carbon

.4 nozzle

.2 mm layer height

100% infill 

No supports needed