lots of information all over the place.....We use strictly Iwata guns. We do everything at about 45 PSI hair lines, thick lines and everything inbetween. You have to be able to control your brush which means practice. We use Createx, Wildlife Colors, Golden Airbrush paints and Polytranspar which are all water based paints at the same PSI and never have to thin the paint. You do not have to lower your PSI for fine lines if your gun is working correctly. You have to control the amount of paint coming out of the gun.......and just a bit of fact, Iwata recommends PSI at 25 for artwork meaning paper or fiber board and 50 to 65 for T-shirts and automotive painting. Since we do most of our work on hard surfaces....45 to 65 PSI is the norm....at least for Iwata guns.
Rod