The other day I was reading one of my X-COM books and noticed a big label was covering some text on the back cover. It's been on there since I purchased it from a library which went out of business. Anyhow, the only thing I had on hand was rubbing alcohol so I decided to try it. It works... sort of.
Here's the deal. Alcohol really doesn't dissolve anything. It does however, wet something down without making the item wet (if that makes any sense). It also acts as a lubricant. These properties make it a fairly good choice for removing labels.
Step 1: If the label is mostly intact, try to peel it off first. Most of the time I am able to remove a label completely without the need for other tricks. If it doesn't want to come off, try to get the paper part of the label off. This usually leaves a little bit of the paper stuck to the adhesive part of the label.
Step 2: If peeling didn't work, lay a cloth over the label (assuming it isn't a super-glossy or plastic label) and pour some rubbing alcohol on it. Let that sit for a while and reapply after about 2-3 minutes. By now the label should look "wet". You have one of two options here, either use your finger or the cloth but the method is the same. Lightly rub on the label area until you start to see the paper coming off. Keep rubbing with an alcohol soaked cloth and the adhesive should start to come off as well. At any time if the label starts to dry out, reapply more alcohol until it looks wet again.
That's it. Just keep rubbing lightly and you should be in good shape. No marks are left and the alcohol doesn't degloss the cover or cause the colors to bleed. As an added bonus, alcohol can be used to remove fingerprints on the cover making it look new. I tried this on a number of paperback books with glossy covers and got great results. Scratching a label sometimes leaves marks so don't press to hard. Make sure to do this procedure in an open area with good ventilation and no sparks of any kind. Alcohol is flammable and ignites with a nearly invisible blue flame and can also give you a terrible buzz if inhaled in high quantities. Let me know how you fare, NKF.