Sometimes there isn't room for a door stop, and you don't want to stick a bumper to the wall.

This doorknob bumper cover is designed to fit kwikset tylo knobs with or without locks, though likely can be adapted to other styles by scaling the model.

Print with 2 walls and 10% gyroid infill, 0.2mm layer height.

I used 95A TPU, though any flexible filament should work fine.