I go through so much of this stuff you’d swear I was drinking it. Lighter fluid contains naptha, it will dissolve most acrylic based adhesives, wax pencil and crayon. AND it will evaporate completely.
for a sticker or a library pocket:
1. Using a cotton swab apply lighter fluid/naptha to the edge of the offending item.
2. As the naptha disolves the adhesive, coax edge of label up with paring knife.
3. Continue to apply naptha underneath the edges, peeling up as you go.
4. When removed wash residue off area with more naptha.
if lighter fluid doesn’t work, you may have a non-acrylic based adhesive – like rubber cement. try applying heat using a clothes iron set on low. If you are using it on crayon on uncoated paper, becareful the dyes don’t smear further into the paper.
personally i don’t like Goo-Gone® because it’s greasy and you have to be careful not to put your fingers on the paper afterward, and it leaves a residue. Goof-Off® will also dissolve almost anything including some forms of plastic and the clay coating on a dust jacket cover and then the ink.