Tried to do some true neutral value scales last night with some acrylics using Raw umber, Ivory black and Titanium white. Decided to paint a raven skull with the paint I had left on my palette, I also added some cobalt blue to the mix to get the hue for the background and to deepen some of the blacks on the beak.

Also my scanner has a tendency to really mess up the contrast in any and all pictures I scan :/ tried to restore the contrast by playing around with the curves in PS a bit.