Pull-up bars do not damage a door frame as long as you take precautions. Invest in pull-up bars that prevent scuffing on the side of the frame. These bars feature wide pads designed to add a layer of cushion and not leave a mark. Alternatively, you can cover the end pieces of your regular pull-up bars with non-abrasive material to prevent paint chipping and black scuffing. Simple ways to protect your end-pieces are using socks, thick slices of cardboard, or hand towels.