Red pigments

The color of red and other pigments is determined by the way it absorbs certain parts of the spectrum of visible light and reflects the others.

[2] More recently, pigments were created from dyestuffs from mineral and animal sources, The best known is cochineal, made from insects.

[3] Red ochre takes its reddish colour from the mineral hematite, which is an anhydrous iron oxide, and the main ingredient of rust.

Hand prints made by using red ochre have been found in the Pech Merle cave in Southern France.

Its defect is that it is liable to darken with age, and sometimes develops a purple-red surface sheen, as seen in some paintings by Paolo Uccello, including the bridles of the horses depicts in "The Battle of San Romano" .

[5] Alizarin crimson is a vivid red pigment, inclined slightly toward purple, which was most widely used as a dye.

It has been found on fabrics in ancient Egyptian tombs, and its production in Europe was encouraged by Charlemagne for the early European textile industry.

In the Ming dynasty, (1368-1644), the color was featured in all official ceremonies, including sacrificial offerings, weddings, and departures of expeditions.

Red lake pigments were an important part of the palette of 16th-century Venetian painters, particularly Titian, but they were used in all periods.

[8] Since the red lakes were made from organic dyes, they tended to be fugitive, becoming unstable and fading when exposed to sunlight.

It largely disappeared after the invention of synthetic dyes and pigments, but has resumed more recently because of the lack of toxicity and environmental benefits of the product.