I began by blending burnt orange and raw sienna eyeshadow into the crease.
The lower strata of rocks was deep red, the upper ones of a raw sienna colour.
An imprimatura is usually made with an earth color, such as raw sienna, and is often diluted with turpentine.
It is made by heating raw sienna, which dehydrates the iron oxide, changing it partially to haematite, giving it rich reddish brown colour.
A clay of limonite rich in iron oxide is the source of raw sienna and burnt sienna.
