Every scratch question comes down to one thing: how deep? Get that right and the fix is usually cheap. Get it wrong and you'll polish a hole or paint over a scuff — both make things worse.
The fingernail test
Run a fingernail across the scratch, perpendicular. Thirty seconds, tells you everything:
- Nail glides over it → it's in the clearcoat. Fix: polish. No paint involved.
- Nail catches slightly, scratch is white-ish → through the clearcoat into color. Fix: touch-up paint, then polish.
- Nail drops in, you see gray primer or silver metal → deep. Fix: touch-up in layers, or aerosol for anything long. Don't wait — bare metal rusts.
Fix 1: The clearcoat scuff (most common, cheapest)
Those swirly white marks from a bush, a bag, or an automatic car wash live in the clear layer above your color. Paint is the wrong tool. A dual-action polish or even a decent hand polish with a microfiber removes the scratched clear and blends the edges. Ten minutes. If the mark disappears when you wet it with water, this is your fix — the water is doing temporarily what polish does permanently.
Fix 2: Through the clear, into the color
Now you need actual paint — mixed to your factory code, not a parts-store "universal" tube. The process is the same as chip repair: clean with isopropyl, thin layers with a fine brush, 10–15 minutes between coats, build level, polish after cure. We wrote the full step-by-step here.
Long scratch? A brush line along two feet of door will always read as a line. That's aerosol territory: mask wide, spray the scratch, blend the edges. More effort, dramatically better result on anything longer than a few inches.
Fix 3: Down to primer or metal
Same technique, more urgency and more layers. Metal showing means rust is on the clock — weeks in a dry climate, days in a wet one. Scrape any rust that's started, then build thin layers until level. For our 1K gloss touch-up there's no separate clearcoat step; for traditional basecoat, clear goes on last.
The myths (save your money)
- Toothpaste. It's a very bad polish. On the lightest scuff it sort of works by accident; on anything real it does nothing. A $10 polish does the job properly.
- WD-40. Fills the scratch with oil so it looks gone — until the next wash. It also makes the panel impossible to paint until it's fully degreased.
- "Universal" scratch pens. One shade of clear-ish goo for every car ever made. On dark solid colors, from a distance, maybe. On metallics and everything else — you'll see it every time the sun comes out.
When to call a shop
Honest list: scratches with dents in them, damage across multiple panels you want invisible on a lease return, and anything where the panel edge or bodyline is deformed. Paint fixes paint — it doesn't fix geometry.
For everything else: find your factory color, start with the fingernail test, and match the fix to the depth. That order — and thin layers — is 90% of a repair that looks right.
