I designed these command strip curtain rod hooks because I hate putting holes in my walls. I was going for a design that would be fairly quick to print, and look good without drawing too much attention. This is what I came up with. I use 3 hooks for a fairly light curtain rod and curtain.

I printed these hooks with 5 perimeters and 25% infill. Print the hooks on their side for the best results and no support material. You could then scale the z height to 200% if you wanted to accommodate two strips instead of one for heavier curtains.

I used the Velcro style command strips on these hooks. The other style will work as well since I designed the hook to keep the tab accessible for removal. I recommend using super glue to attach the command strip to the hook to ensure that it doesn't come off the hook. This would really help on plastics like PET-G. Just make sure the glue is completely dry before putting it on your wall!! Your limiting factor that will determine how heavy of curtains you can use will be the command strips.

I may do a couple different versions of this design, so stay tuned for that.