How to Thin Airbrush Paint

Learn to thin airbrush paint with these easy to follow tips, and master the most complex part of airbrushing!

If you’re planning on using an airbrush, you need to get good at thinning your paints, this is an inescapable part of airbrushing.

How to Thin Airbrush Paint

Thinning your paint is sort of the one thing you have to learn when you airbrush.

Even with workarounds like airbrush-ready paints, you hit a point where that paint is too thick and you need to know how to thin it down anyway.  Or the paint you want is already too thin, in which case you need to find an alternative.

The Ratios Can Change

The ratio of paints and how much you thin them changes for almost every paint, and even some paints within the same brand.

This is what makes thinning your airbrush paint so hard, there’s not one set way to do it.  And also where most tutorials fall short, claiming to be the end all be all way.  It just never is.

Lucky for us, there are a few tricks that makes learning to thin airbrush paint much easier.

Disposable shot glasses

Mixing your paint in one of these transparent containers instead of directly in your airbrush is the real game changer.

First, it’s much easier to see what you are doing this way.  Second, you limit the chances of pouring small chunks of paint or paint that’s too thick in your airbrush, which will clog it and make cleaning a nightmare.

Which leads us to this next trick.

Too thin is better than too thick

Obviously, “just right” is the best thinning.  But when you’re still learning, when in doubt thin slightly too much.

  • If it’s too thin, it will spray but not cover very well.
  • If it’s too thick, it might not spray, and you’ll have to clean the airbrush, with paint crammed in there

What to Use to Thin Paint?

There are a bunch of products and techniques you can use.

I personally use glass cleaner.  It’s an old pirate trick, but it’s the way I first learned it and it works for me.  It’s cheap and works well for both cleaning and thinning.

The main thing, and one a lot of people are guilty of is always chasing the next best thing.  Don’t.  Once you find a method you like, don’t keep changing it up.

SAFETY/HEALTH: Whatever you use, but more-so if you use chemical-based thinner like glass cleaner, make sure you are wearing a mask with the appropriate rating to protect yourself.  Vaporizing paint is not part of a healthy diet, even the non-toxic kind.

Some painters swear by only water.  Some use Airbrush Flow Improver or  Vallejo Thinner as well.

How to thin airbrush paint

The common internet saying to thin airbrush paint is “thin paint like milk”.  This is, pardon the technical term, a load of crap.  It’s one of those saying that has been around since forever and that people kept using despite not knowing what it meant.

The reality is, paint thinned down to milk like consistency is too thin for most techniques including priming and base coating, two of the main reasons why people want to use an airbrush.

The only redeeming quality of ‘thinned like milk’ is that it is on the thinner side, so you can simply add more paint to that mix until you find the sweet spot.


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