The Old Masters would paint in monochromatic tones beneath their paintings, and then build them up with layer upon layer of washes, carefully mixed with egg to allow them to have just the right translucence to let the richness of the underpainting show through. Then, along came other schools of thought-- like Van Gogh, who would dash paint onto the canvas in the heat of the day, breaking rules left and right, using paint right out of the tube, portraying the sun as a round orange in the middle of the sky. His underpainting was nothing more than a quick outline in black.
Maybe what got me thinking about this was a workshop I took this winter... the course instructor taught about painting "hot" colours beneath the light sources. Like how a blue sky (blue is a shady, "cool" colour) is actually, when you look out your window, the brightest part of the view. So how do you make your canvas "read" like real life? Her solution: paint pink (a warm colour) beneath. Underpainting.
I've been honing this a bit, trying to use her wisdom without stealing her style.
So when you look at this cow number 25, I thought you might be interested to hear about the underneath layers... the purples beneath the red of her coat, the blue in the eyes.
18x18" acrylic on canvas