What is wrapping foil on door knobs?

Wrapping foil on door knobs is a technique used to protect them from paint splatters when painting doors. By wrapping the foil around the door knob, it creates a barrier that prevents any paint from getting on the surface of the knob. It is an easy and cost-effective way to protect door knobs during the painting process. Additionally, the foil can be easily removed once the paint has dried, leaving the door knob looking as good as new.