I was delighted to be able to spend three hours working on this portrait of Tony. We had a nicely dramatic low light source and Tony held his pose wonderfully.
The Finished Painting
Even as I was painting, though, I knew I hadn't gone dark enough with the left side of the face.
When this happens, I tend to paint away to a finish from the model (second last picture above) and then a couple of days later add a dark glaze over the area where the darker tone should have been.
Here I used liquin tinted with burnt umber and alizarin crimson. The good thing about this process is that it saves all the modulation in the initial painting but just darkens the area by a few degrees giving the painting a much more palbable sense of drama.