Well it is kind of a broad question with alot of variables. With that said the inlet pressure will depend on which gun you are using. If it is a typical HVLP gun then they run anywhere 15-35psi inlet pressure, 15 being on very low side. I have found the best pressure setting to be 30psi for base and 35psi for clear. The overspray was not too bad with great atomization at that setting. For spraying the primer I used 30psi inlet pressure with 1.8mm needle tip. Also for the bc/cc I used 1.3mm needle tip. Now depending on the mixture, temperature and humidity you might have to run lower pressure. I would say those are the ball park numbers.