- 40% paint
- 50% water
- 10% flow-aid
If you haven't used flow-aid before, it's a Liquitex product and its amazing. I use it to make washes flow even better into spaces and I use it when cutting my airbrush paint to help get the paint through the nozzle.
I also went through one additional step and used an automotive disposable paint filter to run the paint through. I'm not sure it did anything though I can say with the above two steps I had zero problems spraying ten models and zero problems cleaning up the brush. We'll see how the above method holds up when I paint the first batch of 20 Mk3 marines. That will be a bigger test.
Filter I used.