To Grisaille or or not to ...
It is up to you, the artist, to decide what style you want to use when painting a portrait. There are many different styles that include or don’t include a preliminary coating of the canvas. I often prefer to do a painting directly on a white canvas, as it will keep the luminosity of pure bright colors rich and strong.
But, there are other times when I want to create more of a ‘deep mood’ than a statement of color. Grisaille painting is wonderful for this reason. You can paint in the moody method of the Renaissance painter with the right knowledge of how it is done.
When I first began painting in 1984, I was taught to paint the whole image with just burnt umber, scrubbing it in thin and literally erasing out my highlights. I still teach some of my new timid students to use this method, as it helps them learn to evaluate value and make their often timid use of value stronger in contrast by force. Since that time, I have learned more about the original use by the masters of painting both warm and cool tones, in values of gray and brown, to emphasize not only the value, but the temperature of the light and shadow.
Grisaille is a method of using gray in the cool tones of your model. Bistre is the method of using brown tones in the warm lights. Together, they create a full range of values that are not only rich in depth, but illuminated with temperature of value. Glaze is added over the top of your Grisaille and Bistre and produce a finished painting. (see the chapter on ‘Glazing’ for more information on methods and techniques).