I doubt that theo's suggestion of an ohmmeter will help at all! ;^)
I used a lightly dampened paper towel or gum eraser in the past. But I like the prospect of slaw's suggestion much better.
Of course it may make a difference between glossy printed covers VS matt paper, the latter being more easily damaged by moisture.
One positive I can recommend is for removing price stickers and labels. If you do any electronics work you may have a heat gun. That can work wonders (with low setting) on even very old, dried out labels. A plastic edged scraper can then make pealing away the label much easier. A hair dryer might work but I expect has a lower heat range.
But another issue is signatures or notes made with a ball-point pen. Years ago there was an ink eradicator easily available but no longer. That may not have been much more than bleach? Any suggestions for this problem would also be appreciated.
I used a lightly dampened paper towel or gum eraser in the past. But I like the prospect of slaw's suggestion much better.
Of course it may make a difference between glossy printed covers VS matt paper, the latter being more easily damaged by moisture.
One positive I can recommend is for removing price stickers and labels. If you do any electronics work you may have a heat gun. That can work wonders (with low setting) on even very old, dried out labels. A plastic edged scraper can then make pealing away the label much easier. A hair dryer might work but I expect has a lower heat range.
But another issue is signatures or notes made with a ball-point pen. Years ago there was an ink eradicator easily available but no longer. That may not have been much more than bleach? Any suggestions for this problem would also be appreciated.