pfr, I use that green, low-tack painter’s tape to mark the position of my Mandolin bridge. Comes off nice and easy and doesn’t leave a mark. I only do it every fourth string-change or so - about yearly - when I want to take all of the strings off and give ‘er a bit of a wipe all over with a damp cloth to get the spit off. Otherwise I change strings in pairs so the bridge stays under tension and in place.

The first time I did the painter’s tape thang, I decided that, after wiping ‘er down with the damp cloth, I’d give ‘er a birthday with some polish. So I peeled the bits of tape off and.....Oh F**k!! Took me forever to get the intonation re-set perfectly. ;-)