Clear-over-Base

Clear-over-base is the modern system for painting cars and the most commonly encountered. It consists of a layer of primer, followed by a base coat of colour, and topped by a thick coating of lacquer which is called the clear coat.

This method of painting has been around for a very long time, but used to be only used on cars with metallic paintwork which was charged at a premium price, with all other cars being a solid colour without a lacquer.

What it means

Clear over base describes the way most modern cars are painted. First a primer is applied, then a coloured basecoat that gives the car its actual colour. On top of that sits a clearcoat lacquer - a transparent top layer that provides gloss, depth and much of the protection against weather and wear. When people talk about polishing or correcting paint, they are almost always working on the clear layer of a clear-over-base system.

Why it matters

Correction happens in the clearcoat and nowhere else. Polishing and sanding are aimed at that top layer, and reaching the colour underneath is a mistake rather than a milestone, which is what makes the system worth understanding before anyone picks up a machine.

Damage sorts itself the same way. Scratches and etching usually sit in the clear, while anything deep enough to reach basecoat or primer has left correction behind and needs repair and repaint. In refinishing the two layers do different jobs: basecoat carries the colour match, clearcoat supplies gloss and texture, and a repair only disappears if both are right.

It also sets a hard ceiling on how much can be taken off, since only part of the total film build is clearcoat and that portion is all the material available for polishing and flatting.

How datasheets refer to it

You will see clear over base mentioned on paint manufacturer datasheets, bodyshop estimates and detailing write-ups. Phrases such as two-stage clear-over-base system, repair clear over base on door or machine polish clear-over-base paintwork are common. It is effectively the standard system on most modern cars, including metallics, pearls and many solid colours.

Context

Clear over base replaced many older single stage systems where colour and gloss were in one layer. In a clear-over-base system, all cosmetic correction work - swirl removal, bird mess etching, orange peel reduction and so on - is carried out in the clearcoat. Detailers measure total paint thickness, then work with the understanding that only the top portion is usable for correction. Bodyshops follow paint system guidelines on film build, flash times and curing to ensure the clear over base finish stays stable and does not suffer from die back, solvent migration or other defects.

Common mistakes

• Assuming deep scratches in a clear-over-base system can always be polished out, even when they have gone through the clearcoat into the colour.
• Over-polishing clear over base paint without checking thickness, eventually thinning or burning through the clearcoat.
• Comparing modern clear-over-base finishes directly with older single stage paints and expecting the same behaviour when correcting or restoring them.
• Judging a respray only by colour match and ignoring a mismatched clearcoat texture or gloss, which can still give away a repair on a clear-over-base system.

Authored by Danny Argent. Reviewed by Gary Wray. Last updated 16 May 2026.