Art Glossary: Underpainting

Underpainting with oils
Underpainting done with a mixture of cadmium yellow and burnt sienna. Paint removed from the areas that were to be the brightest with a sponge dipped in turpentine, establishing the overall dark-light pattern. "Aisle of Snow" Painting © Mirjam van den Bos 2010. Oils.

Definition:

The initial or lowest layers of paint put down in a painting, before the details of the painting are put down. Some artists use underpainting to establish tonal values in a painting, effectively painting a monochrome version of the final painting to get all the tones right before adding color. Others use underpainting to establish areas of color as a first step in building up colors through glazes.

Underpainting doesn't need to be done in gray, it can be done in any color(s). It can be very effective to create a cool or warm underpainting as a contrast to warm or cool colors in the final painting, letting the underpainting show through in small areas.

An underpainting done in greys or browns is known as grisaille. If you use green-greys, it's called verdaccio, and if you're using a transparent color it's called imprimatura.

See Also: 7 Ways to Create a Painting