This
is an Old Master technique that makes use of glazing--the process
of applying many thin layers of color over an underpainting to build
up subtle, jewel-like tones. The painting is begun by priming the
canvas with a color, usually a pinkish or yellowish ground, to unify
the color theme. Then the design is laid out on the ground. One paints
over the whole canvas with a darkish color that will eventually become
the shadows. Then any part of the painting which will finally be in
the light is "wiped out" with a cloth or a tool. Since the
dark color is covering all the layout marks, and the paint is drying,
this can be a challenge...
After the "wipe-out" is finished and the gradations
of light and shadow have been made, the brightest lights are underpainted
with white.
The background is
painted, then the colors are glazed on in translucent layers. Each
object might have many layers of slightly different colors to add
interest and subtlety. Since a layer of oil paint has some thickness,
this build-up of layers eventually contributes to the sense of depth
as the light strikes down through the colors to the white beneath.
