Painting a Head

It's been awhile since I've painted from a model, I went to scottsdale Artist School last Saturday and painted a head. I know some artists who seem to never lose their chops. For me, if I'm not doing it regularly, I feel it. I had to really work on this. I painted a couple of hours at the school and then reworked it for a couple more at home. Although I see more I should do with some of the forms, it's now fairly satisfying. But I see I need to be doing this more often.