I was looking for a way to speed up my painting and decided to try airbrushing contrast. As you can see, the result is fairly decent considering the time spent.
What you see here is a zenithal priming (black, grey then white) followed by airbrushed skeleton horde (with about 20% thinner in it).
Looks great! I just discovered this too a couple weeks ago (albeit using Army Painter speed paints). I always struggled with brush stroke lines with speed pains but the air brush made great work.
I have started painting my test tyranids from Leviathan and I'm going with a similar scheme, at least for the skin portion. Do you get much from the zenithal priming that the contrast doesn't do already or is it to double down on the contrast effect?
On a recent project, I simply primed white, and some hard to reach parts of the model remained white, which I really disliked, because I spent a lot of time teaching these unpainted parts.
Zenithal makes the model white, while still leaving the hard to reach parts black, which registers to the eye as shadow and gives, in my opinion, a better result with less efforts.
Contrast also makes the transition between white and black (light and shadow) really smooth and natural, even on brighter colours.
Yeah, it actually works kinda like a glaze if you airbrush a thin layer, or you can do like you did, spray a bit thicker and it'll still do the contrast effect. But that doesn't work too well with some colors