Sienna earth pigments are named for the Italian city state of Siena, where they were produced and widely used during the 15th-16th Century Renaissance. Raw sienna is a yellowish beige, which becomes redder as ‘burnt’ sienna when it is heated.

Sienna clay was known as an artist’s pigment to the ancient Romans as terra rossa (red earth), and was used by Ambrogio Lorenzetti (c.1290-1348) to paint The Allegory of Good and Bad Government (opposite) and later by Caravaggio and Rembrandt.