In these paintings  I’m working on comparing light and dark areas on still life and landscape scenes. 

I start by creating an under-painting in one dark color such a brown or purple.  To focus on the lights and shadows I paint in the dark areas more thickly and I thin out the paint in the light areas.  This lets the white of the gesso show through.

After the under-painting is complete I add the colors over this, being sure to keep the light, medium and dark values I have already put down. I work over the under-painting of values while it is still wet.  I allow all the paint to blend together.