I work with automotive paint every day and daggerlee is right. We use the Dupont paint system at work and its pretty close to what daggerlee said before. The carrier is what makes it flat/semi gloss/ gloss, not the way its sprayed on. With a base coat/clear coat system on vehicles, binder and balancer are added to the paint as the carrier , and when ready to paint reducer is added to the mix other wise it wouldnt spray, or dry worth a crap. The basecoat, (paint) dry's on flat, and then clear is sprayed on to make it shiny, and for protection. If you were to ues single stage paint ,the carrier thats added makes it glossy/semi gloss/flat etc. and no clear is sprayed on or is needed. Pretty much what was said befor but oh well.
PM me if you use any automotive paint and have any questions. I'm sure i can help!