Hard thing to nail down, being honest. I'm learning (as someone who is somehow challenged) that "acrylic" paint does not mean the 1970s poster-crap. To add to that there's at least 3 (maybe 10, my head spins) different types, which all want their special thinner.
I do not use a tank (required for anything "precise" as to pressure), but in general I dilute at LEAST 50% for the airbrush and run under 20PSI often tuning down to 12 or so. I learned the airbrush with watercolors, no modelling by me for the 1st ten years I owned one! But that method/discipline (watercolor is all about preserving white space) transfers well to this space. Spray thin, chill out, keep going, that has worked well for me.
My brush uses a 0.05 nozzle/needle (Iwata, gravity-feed, dual-action), I am always between 12 and 20 PSI, with HEAVILY diluted paint.
Being patient and understanding that modern acrylics are fragile AF(!!), sigh...again...I am learning.
