How To Thin Acrylic Paint For Airbrush - Airbrush Guru

How To Thin Acrylic Paint For Airbrush

Reducing or thinning airbrush paint in many cases takes a bit of experimenting to find exactly at what consistency the paint atomized best in the airbrush you are using.

Thinning Acrylic Paint

The general rule of thumb with most Acrylic Colors is reducing it with distilled water or airbrush reducer until it flows like milk.

A lot of things come into play when finding just the right consistency of the airbrush paint you are using to atomize correctly. The type of airbrush you are using, needle and fluid nozzle size and the air pressure you are using all come into play.

The amount of reduction also depends on the size of the nozzle in your airbrush; 0.5 mm nozzle will spray much thicker paint than a 0.2 given the correct air pressure is being used.

Over reducing some paints might have an adverse effect and the paints might not adhere as well. Always check the product tech sheets if available. Key to this is experimenting to find what reduction works best for you and you situation.

Airbrush Extender Vs Airbrush Thinner Vs Flow Improver

Airbrush thinner is for thinning paints while paint extenders that the paint companies make, more often than not, do not make the color thinner but do make it more transparent.

On the other hand, Flow improver is medium used to improve flow of paint and it helps to avoid tip drying. You can add couple of drops of flow improver in the airbrush and it will improve flow.

Below is some information I have put together for several different products, I hope you find it helpful.

How To Reduce Auto Air Colors

0.3 mm needle, nozzle size – Transparent Colors thinned with Auto Air Reducer approx 300% or more (3 Reducer : 1 color)

0.2 mm needle, nozzle size – Transparent Colors thinned with Auto Air Reducer approx. 500% or more (5 Reducer : 1 color)

***To improving atomization when using an airbrush, Auto Air Reducer may be used to thin paints. Often, colors are reduced up to 400% (Auto Air Reducer 4:1 Auto Air Color) when using an airbrush. Mix ratios may vary per color and Color Series. Exact ratios are not required.

How To Thin Createx Airbrush Paint

All the Createx Illustration Colors, Auto Air Colors and Wicked Colors can be reduced by using 4012 high performance reducer.

Their performance can be further improved by using 4030 Balancing Clear. This is a clear base medium than can increase durability and spray performance and works as a adhesion promoter.

Here is a nice video explaining how to reduce Createx airbrush paint. [chart showing reduction matrix]

GOLDEN Airbrush Colors

GOLDEN High Flow colors are formulated from a safe and archival 100% water-based acrylic emulsion, incorporating only the most light fast pigments available. They are ready to use, no dilution required as they are finely ground, they easily spray through the smallest orifices available for airbrushes.

GOLDEN Airbrush Medium (formerly Airbrush Transparent Extender) can be added to the Airbrush colors to yield more transparent colors without jeopardizing the film integrity and permanency. In fact, lowering the pigment load by adding the Extender will actually increase the film’s durability and frisket performance.

Here is a Paint mixing ratio chart I came across on various forums showing what ratio should be used to thin various brands of paints.

Paint ThinnerRatioPressureClean-Up
Polly ScaleDistilled Water3:1 or 4:115-25H2O/Washer Fluid
FloquilSolvent/Thinner2:1 or 3:112-20Lacquer Thinner
Badger ModelflexWater Very little, if any 25-30H2O/Washer Fluid
TamiyaAlcohol2:115-20H2O/Washer Fluid
Vallejo Model ColorVallejo Thinner3:120-25Lacquer Thinner
Vallejo Model AirVallejo Thinner Very little, if any 20-25Lacquer Thinner
MicroLuxVallejo Thinner Very little, if any 20-25Lacquer Thinner
HumbrolWater1:1 or 2:115-20Water
GunzeSangyoAlcohol or
Distilled Water
1:1 or 2:120Water/Alcohol
Scalecoat IISolvent/Thinner1:115-20Lacquer Thinner
ModelMaster(Testors)Universal Thinner Very little, if any 18-20H2O/Washer Fluid
Alclad IILacquer Thinner    Very little, if any 12-15Lacquer Thinner
PactraLacquer Thinner1:120-25Lacquer Thinner
Pactra AcrylicNone 25-30H2O/Washer Fluid
Lifecolor AcrylicDistilled Water, Washer Fluid1:112-15H2O/Washer Fluid
Craft Store Acrylics25% Liquitex Slow-Dri, 25% Flow Improver, 50% water1:220-30 


Thinning Solvent Based Paint

Solvent based paints are a hard one to discuss as there are so many different systems out there on the market.

By solvent based I’m referring to the automotive paints we use for airbrushing murals, flames, graphics on bikes, cars, trucks, etc. With these the best thing to do is to get to know your local paint jobber REAL well.

Most if not all the tech sheets put on these products, relate to painting cars and not to applying these products through an airbrush, please keep that in mind when reviewing tech sheets.

Most often when used in an airbrush, you must over reduce the products beyond what the tech sheets say to get them to flow correctly through an airbrush.

Thinning solvent based paints is a very personal choice as to how much you thin or reduce it, this will take some experimenting on your part I’m afraid.

With the House of Kolor paints, I generally reduce it with slow reducer at about 50% paint 50% reducer depending on the color maybe a bit more reducer. The tech sheet calls for two parts paint one part reducer for spray gun applications on most House of Kolor products. So you can see, I do over reduce it according to what the tech sheet says. Again a good starting point might be to get it to flow like milk.

Beware of using a solvent based product in your airbrush that requires adding a catalyst. I will add more to this page as time allows please book mark this page and come back often.

I hope you found this helpful in sorting out how to find just the right consistency the airbrush paint you are using flows best.