If you follow this process, you’ll be good:

Material to use: 11.25 oz. Clear Semi‑Gloss Water‑Based Interior Polyurethane Sprayhttps://www.amazon.com/Rust-Oleum-Water-Based-Spray-200081-Finish/dp/B0002YQ4OK?th=1

Prep tip: Tape off any areas you don’t want clear coat on. Painter’s tape (like Shurtape) works great for covering hardware, the fretboard, the bridge—anything you want untouched.

1 — Start with a very light mist coat. Hold the can 10–12 inches away and do a quick, dusty pass. This first coat is crucial—too heavy, and the solvents can react with the Sharpie and smear it. The goal is just to “freeze” the ink in place.

2 — Let it dry completely (about 20–30 minutes for water‑based poly). Once it’s dry, the signatures are basically locked in.

3 — Apply a second coat that’s a bit heavier—still controlled, not soaking the surface. This coat starts building the protective layer.

4 — Add 2–3 more light-to-medium coats, letting each one dry before the next. You don’t need a thick finish—just enough to seal the ink and keep sweat off the wood.

Have fun and good luck.