A Grisailepainting of "Princess de Broglie" after Ingres

The clasical "GRISAILLE" (grey, no coulors) underpainting was used in the older painitng-technique to determine the denominations (light/shadow )

and the fine details before they where overpainted with transparent Colors of special sun-thickened oil including resin and other secret fluids.

The copy benfits from this thechnique to get a result as simular as possible to the original.

In this case there is only used Temperawhite, covering or semi-opaque . (half-shade)

The grey Gesso is the only other color which give the shadows. Some charcoal can also be visible.

Wikipedia says: "A grisaille may be executed for its own sake, as underpainting for an oil painting (in preparation for glazing layers of colour over it)"