Before you add your aggrelen earth, paint a dark colour all over your base, then coat all of the base with pva glue brushed on, once that's dry apply the aggrelen earth.
The pva will form a layer for the texture paint to stick to and once the cracks appear you will see the dark paint that you first applied
Cheers All
They are all just about black still so guess I could just go for the PVA right away.
RE my Deathwing, Citadel paint app has for Bone: Zandri -> Sepia wash -> Ushabti highlights -> screaming skull highlights.
These are matched on my TTC stuff:
I think I can get the shading with the airbrush, but if I want that shading right at the bottom of the legs I will need to try and glaze it:
Like on the bottom of the right leg (as we see it). Or can that be achieved with teh airbrush somehow?