I’ve never been able to go less than a 50/50 thinner to paint ratio on these paints. Using a medium tip, I start with a 70/30 with 20 psi. Thin coats with fast drying and great coverage. I’m a real fan of these paints as I can brush when I need to and AB when I need too. I use 91% Isopropyl Alcohol or water. I find the acohol (or my perception) that it has a less chance to run.