Spotlight on Sienna
Sienna was one of the first pigments used for painting and can be found in prehistoric cave art. It was not until the dawning of the Renaissance in the 14th century however, that the pigment was further developed for artistic use. It was also during this time that it was named after the place that it was found, Siena, Italy. During this time the Italians enhanced the range of hues for the pigment by roasting sienna leading to the creation of Raw Sienna and Burnt Sienna pigments. These earth colours featured heavily in Renaissance painting techniques.
Historically, the highest quality artists' pigments came from clays collected in Italy, Cyprus and the Middle East. Pigments from the Middle East were imported to Europe by Venetian merchants. During the last two decades, however, the Tuscan deposits of Raw Sienna have become depleted so Italian siennas have come from other locations such as Sicily and Sardinia. Small quantities of sienna have also been mined in Germany's Hartz Mountains. The quality of these alternative ores are not always of the same quality and have led Colourmen to look to synthetic pigments.
Until 1988 Winsor & Newton bought sienna pigments with a beautiful bright undertone from a mine south of Sienna, the mine was closed. As a result we bought the remaining stocks which lasted up to 1991. After this, there were no potential suppliers of siennas with the same bright undertone; however, transparent synthetic iron oxides had already been on the market for some time. These were evaluated and found to have the same transparent undertone, closely matching old standards, especially in water colour and are used today.
*Earth colours are a collective term given to naturally occurring colours which come from the earth (i.e. iron oxides which come from clay). These include Yellow Ochre, Raw Sienna, Burnt Sienna, Raw Umber, Burnt Umber and Terre Verte.