How do you airbrush nail polish? o_O

You make it very thin with acetone first and you make sure you wear protective face gear so you don't breathe the chemicals in when you spray it! I make sure I wear a medical mask. I add acetone to the nail polish bottle itself to thin the entire bottle. After that I put it into my well and add even more acetone to it after it's in the well so that it's as thin as possible. My airbrush is portable so the pressure can't go that high, it can only go to about 40 psi, so it has to be very thin for it to spray. The thickness of the nail polish has to do greatly with your compressors pressure capacity and your gun itself, but in my opinion and my experience, thin is good! (It also really depends on your color, some colors are thicker or goopier than others) I hope this was helpful!

Huh, interesting! What advantage does nail polish have over other enamel-based paint?

Well first off, ITS SPARKLY AND SHINY WOW!! The iridescent effect is FANTASTIC. The picture does not do it justice. Hell when you paint it on your nails it doesn't do your nails justice. For some reason when I mixed it with the acetone and airbrushed it, it brought out the sparkle and it just looked amazing in that clear globe. I can't wait to try it on an eye with a pupil. I feel as though it bonds to the resin better than acrylic paint as well. Acrylic almost sloughs off but this sticks down especially when I seal it. I just like the way it looks more so than acrylic.
It looks more realistic to me.
A big disadvantage though is you have to REALLY REALLY clean your airbrush after the use of nail polish.
I super clean my brush after every use regardless, but you gotta soak it in acetone after you use nail polish so it doesn't dry in the airway.