get paint or decals that crinkle up, and sometimes it goes on smooth. The only rule is "Test, test, test". Run a "test coupon" using some disposable material. We do it when we heat-treat aerospace parts, why not do it for model cars!?!? Or just buy the tried-and-true stuff. Today, I suppose that's Tamiya. I'm so happy I bought a whole bunch of Testors enamel in glass jars, including a lot of Boyd's colors, and still have a bunch of Testors air brush thinner. Can't recall ever having problems with that stuff.