So to simulate this experience I brought up one of my photos of the wonderful Inukshuk (the adult male bear at the Toronto Zoo) on my laptop. I positioned my laptop at a distance and height a human model would sit in front of the easel. Imagining the model before me was 3D, I blocked in the shapes, values and colours I observed on the blank canvas. There was nothing drawn up before hand.
In this style of painting, the background is more than a backdrop of colour to hide the white canvas. The paint helps carve out and define the outer edge of the head, helping it to stand out from the canvas. Only at the end of the portrait painting are the fine details, and pure blacks and whites added.
Of course, for me, whether the portrait subject is human or otherwise, the big reward is always when I get to finish the eyes. Thanks to the magic of oils, the polar bear eyes in these portrait paintings, as well as in my imagination, are very much alive.
P.S. There is another male bear at the Toronto Zoo, Toronto, Ontario, Canada. Humphrey, the polar bear cub of Inukshuk and Aurora, turned one year old this past week. He's a charmer, who got off to a rough start, but thanks to the Toronto Zookeepers round-the-clock dedication, he survived.