Interesting Hell Dorado tutorial by Thomas David

When I started reading this tutorial on painting Helle Möller by Thomas David I thought this was just another ordinary step-by-step guide. But when I scrolled down I noticed the special type of basecoat Thomas used... He started out with a black primer, and then used his airbrush to spray on a layer of dark gray, then two layers of khaki and finally a layer of khaki mixed with white. He held his airbrush above the model, pointing down to achieve a natural looking shade on the model.
So far so good... I've seen numerous people doing this with black and white primer. But I was really amazed how easy it was to paint the skin: Thomas used several glazes of skin color, followed by one was of ink. And check out the final result of the skin on this picture.

Pretty amazing huh?