This is the "second under painting" layer, called a closed grisaille. I'm still working monochromatically, as with the previous layer of transparent underpainting, but I'm using opaque paint, meaning the light areas are white paint, not just rubbed through to the light panel ground.
I'm trying to set up a base layer that will help me when I am working on smaller details in the final stages. I want each large area to already have a defined value range, so I don't make the darks too dark and or the lights too light within a given area.
I'm also avoiding painting the lightest lights or darkest darks at this point because I want to reserve the option to punch a dark back,or pop a light out from this range of midtones.
Once this layer is dry I think I'm ready to move on to the fun part, the actual painting.