Just about to decorate lounge (rewallpaper) took mirror down to try and sell and there is some black soot on the wallpaper. This has come from the woodburner could it happen again? I would like to sell the mirror and put something else up poss. wallart but if the black soot thing comes back it will show (can't wipe off as am having textured wallpaper in cream) yes I know! Do I put back the mirror I don't like in case the soot returns or take a chance? Put up wallart/picture? Thanks.