Wednesday, September 8, 2010

The Subject of Art #11: The History of Colors, Chapter 2 - The Toxic and The Fugitive!

In Chapter 1 of this series, we looked at the Earth Pigments, which were readily available in the ground and needed only to be dug up, sifted for purity and mixed with the binder to create a variety of reds, yellows, and browns.

However, these hardly represented the full range of colors found in nature and it became an obsession for artists, and the chemists who supplied them with new paint colors, to develop new pigments that had greater intensity and could cover the varieties of blues, greens and violets that were completely missing in the Earth Pigment range. Unfortunately, the vast majority of these pigments proved to be failures over the long term because they were either terribly toxic, resulting in a variety of neurological disorders or possibly even death to many artists over the centuries from over-exposure, or they were fugitive, which is a term that is used to denote a pigment whose color fades over time when exposed to light. It was not until the mid to late 19th century, with the advent of industrial manufacturing processes, that stable, reasonably safe pigments were developed to replace the more dangerous ones.

Let's take a look at a few of the most popular ones that had been used over time and see what they were eventually replaced with in the palette of colors that we have today!

Toxic Pigments
Of all the most toxic pigments that were used in the history of painting, the most popular was definitely lead. Although we are most familiar with lead as a dark, almost black color that was used in pencils, through various chemical processes lead could be altered to create very bright, intense hues of white, yellow and red.

Up into the 19th century these were known by the names Flake White (also the Cremnitz White which is still made by Old Holland), Chrome Yellow and Chrome Red. Lead is, extremely poisonous and can be absorbed both by ingestion and through the skin, but in it's day it was both cheap and extremely durable, so it was often the choice not only for artists but for house painting and other large scale, outdoor applications. Although true Chrome Yellows and Reds have disappeared entirely, Flake Whites can still be found on occasion and it is still considered by some artists to be far superior to the pigment that replaced it, Titanium White. Chrome Yellow and Chrome Red have been replaced by Cadmium Yellow and Cadmium Red respectively, which are still toxic pigments but far, far less so than their lead-based predecessors.

Unfortunately, we find that lead paint is still used indiscriminately in some parts of the world with no thought to public safety. In 2009 a scandal broke in which a variety of toys manufactured in China for sale in the United States were found to be coated in lead-based paints, resulting in a massive recall to prevent children from becoming sick.

Among the other very popular pigments that turned out to be deadly are Vermilion, a very bright red-orange pigment originally derived from the mineral cinnabar, but which was synthetically produced by alchemists in Europe as early as the 12th century. An important component of Vermilion is mercury, a highly toxic chemical that can be absorbed through the skin and should be avoided at all costs. In the contemporary palette, Vermilion has been replaced by Cadmium Red Light. Another pigment that was both well-used and dangerous was Emerald Green, popularly known as Paris Green in the 19th century, which was made from copper acetoarsenite, a variety of arsenic that was also used as rat poison! The symptoms of arsenic poisoning have led some researchers to conclude that the blindness that Claude Monet experienced towards the end of his life and the neurological disorder that resulted in seizures for Vincent Van Gogh may have been caused by arsenic exposure from the Paris Green they were using in their paintings! Fortunately for us, Emerald Green has been replaced by the infinitely safer pigments Viridian and Phthalo Green.

Fugitive Pigments
Fugitive pigments were far more common than the toxic ones, but for most of them there is little evidence remaining except for written accounts of their use, since they have all disappeared over the years. The civilizations of Ancient Greece and Egypt were colorful places, but little remains now besides the bare stone faces that have been denuded of their fragile paint layers. The only remains that we have are in places that were found to be airtight and dark: the tombs in Egypt and some of the rooms of houses in Pompeii and Herculaneum that were buried in the eruption of Vesuvius.

From those testaments we can see that there were a great variety of colors that were used by ancient artists and that most of them were fugitive and disappeared quickly in the light. Fugitive pigments are typically those that are produced from plant and animal sources and so they lack the durability of their mineral counterparts. Carmine, for example, is a crimson red color that was manufactured by boiling thousands of cochineals, a type of scale insect, and it was the primary source of crimson for both paint and dyes for hundreds of years until it was replaced by the modern colors Alizarin Crimson and Naphthol Crimson, both of which are still moderately fugitive, but much less so than the original.

Likewise Tyrian Purple, which was the royal color of the Roman Emperors, was produced by rendering down a particular species of sea snail, requiring hundreds of them to be caught and processed and resulting in a pigment that faded rapidly, but no other source for violet was readily available until industrial manufacturing produced Manganese and Cobalt Violets and in the 20th century Dioxazine Purple became the standard.

Other popular colors that have not stood the test of time include Sap Green, originally made from the juice of buckthorn berries, which has now been replaced by a mixture of modern pigments. Indian Yellow, a bright yellow-orange, was originally produced by force-feeding cattle with mango leaves and then collecting their urine, which, when dried, resulted in intensely colored crystals that could be mixed into paint. Indigo, the color used to dye blue jeans today, is actually one of the oldest dye colors, having originated in India where the indigo plant is native and quickly spreading to Ancient Mesopotamia, Babylon, Greece and Rome. The synthetic replacement for the natural and fugitive Indigo was developed around 1865, after which use of the plant dye disappeared rapidly.

Through this survey of the failed pigments of previous eras, we can see how art and technology have advanced together, bringing us the paints we use today that are both safe and long-lasting. Enjoy!

Are there topics on the subject of art that you'd like for us to cover? Comment and let us know!

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