Even if you brush paint, I've discovered that it goes better if you thin the paint. Nowadays when I open a new bottle of enamel, I add three or four drops of thinner and a dozen or so pellets of #12 birdshot (to help when mixing - shaken not stirred) without even thinking about it. I use DuPont 3812S enamel reducer as thinner - works just like OEM thinner for Model Master, Humbrol, Testors (small bottle) and even in the few bottles of Pactra I have remaining. Initial cost is somewhat higher - 21 to 25 bucks a gallon, but as a gallon will last me 2 to 2 1/2 years, (even with airbrushing), I figure that's a lot cheaper than the equivalent amount of thinner purchased in the small bottles at the LHS.