Rubbing alcohol lifts ink off plastic.

Rubbing alcohol is the best first try for getting ink off a plastic pencil case.

Plastic is non-porous, which is good news: most ink sits on the surface instead of soaking in. A cotton swab or soft cloth dampened with isopropyl alcohol will dissolve the ink almost immediately. If it’s dried on, press the alcohol-soaked cloth against the stain for about a minute first, then wipe. Hand sanitizer works in a pinch since it’s mostly alcohol.

Skip the magic eraser unless alcohol fails — it’ll scrub the stain off, but it’s mildly abrasive and can leave a dull patch on glossy plastic. Also skip acetone/nail polish remover: it’ll take off ink but can melt or cloud some plastics, and you don’t want to trade an ink stain for a ruined case.

One tip: test the alcohol on a corner or inside the case first if it’s a colored or glossy plastic. Then just wipe and rinse with soapy water. This is a five-minute fix, not a project.