Just taken off my frame bag, and its rubbed some of the paint off down to the frame (forgot to put tape on that bit)
Best way to protect the frame (its steel) before i tape it up before the next trip. Not too fussed if its not pretty, just want to protect the frame from rusting.

Depends how permanent / tidy you want it to be.

Could try painting it, or if you're not ready for that, then gaffer tape over it - that'll stop it getting worse and stop it rusting.

rub off any rust with some fine sandpaper, this will also key the surface.

Paint on (carefully) some primer.

When its dry, sand it back a little (gently!) to get it a little lower than level with the existing paint (do by touch).

Then topcoat with paint. maybe 2 coats depending on thickness.

If your fussy some clear lacquer to top it off.

G