A razor blade can be used to scrape off paint from glass. Use solvent on paint for graffiti removal and wipe off immediately with a clean rag and rinse thoroughly. Be careful with lacquer thinner type solvent on Plexiglas as it can potentially make the surface foggy and smeared. On surfaces like fiberglass, use acetone based solvents but be careful and test it on a small area first as it may dissolve the plastic.
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