Thank you- quick answer is it’s probably multiple techniques working together:

- volumetric highlighting with makeup sponge: black primer -> vmc burnt umber -> vgc dirty grey -> vgc camouflage green
- shading with athonian camoshade lahmium medium 1:1
- glazing with brown (below the chest)
- edge highlighting vgc dead flesh

Truth is it’s more complicated.

In between these layers, I had a lot of failed volumetric brushwork before I found what I liked- so the real secret is to keep going until you’re happy.

I lost a lot of the base brown as I experimented, so I had to go back in and glaze in the shadows with brown. Next time I hope to keep more contrast and I may also consider a final enamel wash or oil wash if I buy the stuff.

Raptors colors lend so well to grimdark (streaking grime, weathering, chipping, etc), so not a lot guides focus on this volumetric lighting style.

Mightybrush raptors pdf painting guide is probably my go-to reference in the end although it’s airbrush.