siennas

Siennas refers to the group of earth pigments commonly known as sienna pigments, most notably raw sienna and burnt sienna. The name derives from Siena, a city in Tuscany, Italy, where the pigment was historically sourced. These pigments have long been used by artists for their warm, earthy tones and natural appearance.

Both raw and burnt sienna are iron oxide–based earth pigments. Raw sienna is a yellowish-brown pigment formed largely of hydrated ferric oxide with trace minerals such as manganese. Burnt sienna is produced by calcining raw sienna, heating it to drive off water and alter the mineral structure, which yields a deeper, reddish-brown color. The two forms cover a spectrum from yellowish-brown (raw) to rich reddish-brown (burnt), allowing a range of shading and tonal options in painting.

Historically, sienna pigments have been used since antiquity and played a prominent role in Renaissance art. In modern painting, they are employed in oil, watercolor, and acrylic media as warm earth tones for underpaintings, shading, glazing, and color mixtures. They are valued for their natural look and relatively good lightfastness, though performance can vary by source and manufacturing method. While contemporary supplies may include synthetic or stabilized versions, traditional raw and burnt sienna remain common choices for artists seeking authentic earth colors.