A quickie lesson in layering warm and cool paint

[Karin Wells]

How do you get that 'hot' color besides just using red? How does it look like Rubens did it here?

There are lots of ways to do this and the easiest is to glaze a "hot" color into the deepest shadow....it does not have to change the color, but it adds warmth. i.e., try a thin glaze of cad. orange, indian yellow, or alizarin crimson.

I understand how reflected light within a shadow is close to pure color, but could you explain why you mix two color opposites? Is it because two color opposites give you some 'movement', some excitement/light in the reflected shadow? This makes me think of some of the Van Gogh's I saw at the VG Museum, for example green and red to create movement. Is this the same principle you're using?

I can probably agree with all you say but basically I do it because it "looks good." Sometimes a "pure color" also looks good but not as often as this mixture of opposites. What is important is that you do NOT put whatever you used in the light into the shadow area. The value of the shadow must always be darker than any value in the area of light. This can be subtle because it "fools the eye" but if you really look, you will be able to see it in the work of the Old Masters. I think that Vermeer is the easiest to see these important lessons in the layering of warm and cool paint.