How Do You Thin Acrylic Paint for Airbrushing Models?

Airbrushing is an art form in its own right, and just like any other artistic endeavor, the quality of your work is only as good as the supplies you’re using. This is especially true when it comes to choosing the paint and a paint thinner.

If you’re using cheap, watery paint, your airbrush work will look cheap and watery. But your work will look fantastic if you use high-quality, suitably thinned paint that is not too thick nor watery.

In this today’s article, I will give you a detailed explanation of why I think acrylic is the most suitable paint and how to thin it for airbrushing models, along with the types of mediums you can use for thinning.

So, let’s get started with the basic question first…

Can Regular Acrylic Paint be Used in an Airbrush?

Choosing the paint for airbrushing is tricky, as you will have to find a happy medium between the paint being too thick and it being too thin – if it’s too thick, it will clog your airbrush, and if it’s too thin, it won’t adhere to the surface properly.

The best way to avoid this problem is to use paint specifically designed for airbrushing, such as acrylic paint. Flaxart suggests picking the acrylic paints labeled “Airbrush Paint,” typically fluid acrylic, which is specially designed for airbrushing use.

Acrylic paint is the first preferred choice for most modelers and miniaturists because its water-based, non-toxic, and easy to clean. These paints also have a fast drying time of about 15 minutes and are ideal for beginners learning how to use an airbrush.

But again, you should remember that consistency of the paint is vital when working with airbrushes. So, let’s see the process of thinning acrylic paint for airbrushing models correctly.

Thinning Acrylic Paint for Airbrushing- The Right Way

To avoid any problems while airbrushing, I would recommend using distilled water or an artist’s reducer. Typically, you should aim to achieve the consistency of the paint that’s similar to milk.

But let me be frank; the process will not be as easy. So, you will need to consider certain essential things to get the desired consistency without creating a messy fluid of no use. These include:

• The type of airbrush you will be using
• The air pressure you will use
• The size of the liquid nozzle and the needle

These factors are important to check, so your airbrush atomizes the color correctly.

Especially for the size of the liquid nozzle, you will find that the 0.5 mm nozzle will spray thicker than a 0.2 mm nozzle, owing to the thickening effect of volume. The best way to figure it out will be to check the instructions on the airbrush you have.

For instance, if your airbrush is a double-action airbrush with a 0.5 mm nozzle, it will likely require a 15-20% thinner medium.

A word of caution – when using a medium to reduce your airbrush paint, make sure you don’t use too much of it as it will result in weakening the paint’s adhesive quality.

A bit of experimentation will be required to get the perfect consistency. And once you have perfect consistency, it will allow you to practice your airbrushing skills without any risk of clogging.

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Best Acrylic Paint Thinner Mediums to Use for Airbrush

There are numerous brands of thinners available in the market that can be used to reduce the consistency of your airbrush acrylic paint.

I have been using Liquitex Professional Airbrush Thinner for quite a while, and I find it very good because it’s formulated to reduce the viscosity of heavy body and high-viscosity acrylics for airbrush application.

Moreover, this thinner will not change the paint’s color, opacity, or durability. You can use it with any airbrush and get satisfactory results.

A few other airbrush acrylic mediums also include:

• Golden Artist Colors (GAC) Medium
• VALLEJO Airbrush Thinner
• CREATEX COLORS High-Performance Reducer

These ready-to-use pouring medium products will reduce the consistency of your airbrush paint and improve its flow. You can find them easily in any good art supply store near you or online at stores like Amazon.

Most brands will have a dedicated acrylic binder or reducer for their airbrush paints. And it helps if you choose the same brand of thinner or reducer as your paint to avoid any compatibility issues later.

Homemade Airbrush Thinner

If for some reason, you cannot find or do not want to use the expensively manufactured reducers available on the market, you can make your homemade airbrush reducer cleaner at home.

Just use one of these recipes that use distilled water as a primary component…

Method 1:

• Add one cup of Fantastik All-Purpose Cleaner to three cups of distilled water in a lidded container or bowl.
• Mix them well and use the mixture with acrylic paint in a 1:2 ratio.
• This 1:2 ratio rule for thinning acrylic paint is simple yet effective in getting the paint to the perfect consistency.

Method 2:

• Add one cup of Fantastik All-Purpose Cleaner to four cups of distilled water in a lidded container or bowl.
• Then add one cup of rubbing alcohol and four to five drops of glycerin. You should add one drop of glycerin to every 50 ml of paint you use.
• Mix all these ingredients well and use the mixture with acrylic paint in a 1:2 ratio.

You can also use other cleaning solutions like window cleaner, etc., in place of Fantastik. But I have found that Fantastik works best as an airbrush thinner for acrylic paint.

Method 3:

• Add equal parts of distilled water and acrylic paint in a bowl.
• Mix them thoroughly to get a homogenous mixture.

Since this method will use only water, it’s not as effective as the other recipes above. But in a pinch, it should work fine, especially for beginners who want to practice on a relatively new airbrush.

Is the paint extender the same as the airbrush thinner?

No, they are not the same but different. Paint extenders help to make the paint more transparent, while airbrush thinners thin out the paint.

A flow improver can also be used to increase the flow of the paint and help avoid the tip drying out.

If you want, you can also use airbrush cleaners as an alternative to thinner and reducers. Many brands will have their line of cleaners that can be used with their specific type of paint. So, it shouldn’t be a problem.

Tips and Warnings:

In all three methods, always use distilled water to make the paint thinner. Never use plain tap water, as it contains minerals that can clog your airbrush over time.

When thinning and mixing acrylic paint for the airbrush, use a container that is tightly sealed with a lid. Add all the ingredients (along with the paint) and shake it vigorously until the paint has reduced to your desired consistency.

If using an alcohol-based solvent for thinning the acrylics, work in a well-ventilated area, as the fumes emitted can be harmful to your health. Once you have mixed the thinner, use a paper towel or cheesecloth to strain it and remove any foreign particles that might have been introduced while mixing the ingredients.

Acrylic paint is water-based, so it is always best to clean your airbrush immediately after you have used it to paint your models and miniatures. If the paint dries on the airbrush, it will be complicated to clean and even damage its internal parts.

What Will Happen if You Do Not Thin Your Airbrush Paint?

While certain brands of acrylics allow airbrushing without having to thin the paint, it is still not advisable.

The main reason for this is that acrylics that come in a ready-to-use state are usually too thick to be used in an airbrush. If you plan to use them, you will probably have to use a higher PSI (pounds per square inch) to get a precise spray pattern.

In the worst scenarios, you will find that your airbrush will clog up or malfunction very quickly if you use the acrylic paint in its original form (straight from the tube).

So, before using acrylic paint for airbrushing, I would recommend reducing it to the proper viscosity with a suitable medium.

The finish of your project will not be impacted by the thinning ratios as long as you maintain consistency throughout the project. Only if you thin the paint too much will it result in a loss of color density and may affect the overall coverage.

That said, there are various paint colors ranging from opaque, candy, and pearl to transparent. Transparent paints allow light to pass through the paint and usually require less reducer than the other colors like opaque (that doesn’t allow the light to pass through).

Also, if you plan to use oil-based paints with an airbrush, be cautious. Not reduce it with water. You should use the reducer that’s formulated for that specific type of paint. For example, if you use lacquer-based paint, use lacquer thinner to thin it out.

Some airbrush-specific brands will have reducers that can be used with water- and oil-based paints. It’s good to check the labels, ingredients of the paint, and the paint manufacturer to see what the recommended thinner is.

The bottom line

Correctly thinned acrylic paints are ideal for airbrushing models, mini sculptures, or miniatures. The type and ratio of thinner you use will depend on the paint brand and your project.

If unsure, always check the paint label or manufacturer’s instructions. Or experiment a bit with the ratios until you get the desired consistency.