Guide

How to fix a car scratch with touch-up paint

Use the fingernail test to see how deep a scratch goes, then fix it with the right method: polish, touch-up paint, or more.

2 min readUpdated October 2026

Whether a scratch can be fixed with touch-up paint depends on one thing: how deep it goes. A few seconds with your fingernail tells you which repair you need.

The layers of car paint

Factory paint is built in layers. From the top down:

Layer What it does What a scratch here looks like
Clear coat Gloss and protection A fine white or light line, the color is untouched
Base coat The color itself The line shows a different shade, often lighter
Primer Bonds paint to the body A grey, white or beige line
Metal or plastic The panel Shiny metal, black plastic, or rust

The fingernail test

Clean the scratch and run a fingernail across it, not along it.

  • Your nail doesn't catch: the scratch is in the clear coat. It usually polishes out with a finishing paste or polish, no paint needed.
  • Your nail catches slightly: the scratch reaches the color. This is where touch-up paint works best.
  • Your nail drops in and you see grey, white or metal: the scratch reaches the primer or the panel. Touch-up still helps, but read the deep scratch guide first.

How to touch up a scratch

  1. Clean and dryWash the area with soapy water, rinse and dry. Any wax or dirt in the scratch will stop the paint from bonding.
  2. Shake the paintShake well for at least a minute, especially for metallic and pearl colors.
  3. Fill, don't paintWith a fine applicator, lay a thin line of paint into the scratch only. Work in short strokes along the scratch, not across it.
  4. Build up in layersLet each layer dry 10 to 15 minutes before the next. Stop when the paint is level with the surface around it.
  5. Clear coatAfter 24 hours, apply a thin line of clear coat over the repair.
  6. Blend and protectWhen the clear coat has cured, work the finishing paste over the area with a microfiber cloth to blend the edges, then wax.

Long, light scratches on the clear coat look worse than they are. Try the finishing paste on its own first; if the line disappears, you don't need paint at all.

Getting the color right

Touch-up only disappears if the color is exact, and the only reliable way to get it is your car's paint code. You will find it on a plate or sticker, usually in the driver's door jamb. See where to look for your brand, or search your brand and code to find your color.

More guides

How to fix paint chips on your carStone chips are the easiest paint repair you can do at home. What you need, the steps, and the mistakes that make a repair stand out.Deep scratches and rust: what touch-up paint can fixAn honest look at what you can repair yourself, how to handle bare metal and rust, and when a panel needs a body shop.Paint code vs. VIN: which one do you need?Your VIN identifies the car, your paint code identifies the color. How to use both to order the right paint.