Thinning Paints



Greetings all! I know in order for my airbrush paint to flow properly I ALWAYS have to thin down my Opaque colours. They are all water-based colour so therefore I use water as my reducer. I read on another thread about people using different psi to control thick paint.

Anyways, I was curious to see what other fellow airbrushers were doing. How do you all reduce your paint? What's your typical reducer/paint ratio? Does psi affect heavy pigmented opaque colours?

Hello Justin,
Well, I'll start with my paints. I'm using very very thick acrylics just because I'm also painting with painting brushes. They're most opaque paints that I've ever used in my life, and very efficient. Without thinning down you can paint almost 30 square meters just with one liter of paint. That's much. But to the point of this topic. In my 18 months adventure with an airbrush I've used a lot of different reducers. Some were better than others, and some were worse. And here's what I've found- best reducer for acrylics ever is... vodka :) Really. Cheapest, worst 40% vodka. It's thinner than water and weighs less, so your piant will flow better. I've heard (and of course tested it) that cleaning solutions for glass (like Windex or Mr. Muscle etc.) are also good. Yes, they're good but you need to be carefull with that and airbrush, 'couse it produses a lot of spume so you can damage your work with that. With regular paint brushes is as good as vodka.

And here are my reducing rations with paints I'm using (by weight)- 2 parts of paint and 3 parts of vodka with Royal Talens Amsterdam paints, and 50/50 with Maimeri Idea Decor paints.

This way you can thin down any type of paint, just with some patience. Simply get some paint into container and add small ratios of reducer (vodka) to it. Look what has happened, and add more if it's still thick. Useful tool for that is an electronic scale :) Using it you'll be able to make identical paint over and over.
Another good idea is to get a piece (I have about 15 cm x 20 cm) of transparent plexiglass. Reduce your paint, put a few drops on plexi and look how its running down. If it's slow, reduce. If it's too fast, add more paint. Coverage of paint should be even and semi transparent or opaque (if tou're using opaque paints) and it's running down should be smooth and even.

Sorry for my English, hope you understand all of that crap ;)



Here's a video I've found about 2 moths ago so somebody just made it faster than I did ;p BUT! Isopropyl alcohol is not a good idea. It's toxic... Belive that vodka is best.
Last edited by a moderator:
Hi I agree 100% with V with his last paragraph and would only add that when watching your redused paint just watch for pigment seperation, if the top of your drop of paint starts to go clear around the edge you have seperation and that is too thin

Hi Justin, to add to the good advice already - i use a 0.3mm setup and usually like to have my paint at the thickness or viscosity of bailey's irish cream. a bit thicker than milk! when spraying at 25 PSI. The paint shouldn't sound too raspy coming out of the airbrush
Makes 20oz of reducer...

12oz Distilled Water
4oz Denatured Alcohol
4oz Amonia Free Window Cleaner clear windowlene is good
10 drops glycerin for the amonia free window cleaner