Acrylic/Poly Thinner X20A 8.5 oz

This was literally formulated by chemists to work well with Tamiya acrylics and it does. It's not pricey at all considering how much thinned paint is actually used when airbrushing. Having around 3-4 bottles of this stuff should let you thin the entire range of Tamiya gloss acrylics and a good amount of the flat colors, too. It sprays perfectly smooth with a 1:1 ratio in my Iwata Revolution CR. I use 12 psi.

Don't get me wrong this product works great and can be used with almost every acrylic. However it is way too expensive for what it is. A 2 to 1 ration water to isopropyl alcohol with a mil of acrylic retarder and (optionally) a mil of flow improver per 60oz batch works exactly the same. A lot of the time more retarder has to be added even when using this product anyway so something good to have on hand. I use Windsor and Newton but Hobbylinc usually has Vallejo as well which is essentially the same thing and works well. Pick your favorite flow improver I use Liquitex because I randomly found it in a shop, but any brand will work. 1 bottle each of flow improver and acrylic retarder will last what seems like forever making its unit cost excellent.

This is the best thinner possible for Tamiya acrylic paints. There is simply no better option. Yes, mineral spirits also work, but not as well. Using a 0.1mm airbrush tip, the default Tamiya ratio of 2 parts paint for 1 part thinner (this thinner) is perfect. There is no other word for it. It never clogged, sprays smoothly with no spitting, and doesn't run. Of course, I am building up light coats, but even then it is still amazing. My only gripe is how expensive it is compared to alternatives. Thankfully, one bottle of this can mix you 34 cups of 3/4 Tamiya paint at default ratio. That should be more than enough.