What is the right thinning ratio for airbrushing?

For acrylics (Tamiya, Vallejo), a starting point is 1:1 to 1:1.5 paint-to-thinner. The target consistency is like skimmed milk — it should flow freely from the airbrush nozzle without spattering. Enamels need less thinning, typically 2:1 paint-to-thinner.

Can I use water to thin acrylics?

Water works for basic thinning but can cause surface tension issues and poor flow. Purpose-made acrylic thinner (e.g. Tamiya X-20A, Vallejo Airbrush Thinner) gives better results because it includes flow improvers and retarders. A small amount of flow improver added to water also works.

How do I know if the paint is thinned correctly?

Dip a stirring stick into the thinned paint and hold it up. The paint should run off smoothly and evenly. For airbrushing, spray onto scrap plastic or paper first. The paint should lay down evenly without spattering, pooling or orange-peel texture.

ModelCalcs

Thinning Ratio Calculator — Paint to Thinner

Calculate the correct paint-to-thinner ratio for airbrush or brush painting. Covers acrylic, enamel and lacquer paints.

Total Volume Needed

Paint Type & Method

How We Calculate This

This calculator splits your total volume into paint and thinner based on the selected ratio.

Common ratios

Acrylic airbrush: 1:1 to 1:2 paint-to-thinner
Acrylic brush: Just a few drops of thinner per pot
Enamel airbrush: 2:1 paint-to-thinner
Lacquer airbrush: 1:2 paint-to-thinner

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates. Always verify quantities before purchasing materials.