A History of Blue Paint
Blue paint was rare or nonexistent prior to the agricultural revolution. Cave paintings were made with relatively readily available materials, and consisted mainly of red, yellow, and charcoal. Naturally occurring minerals such as azurite were too rare and difficult to work with for blue to find its way into prehistoric paintings.
The Egyptians were the first to systematically produce various shades of paint. They used the pigment known as Egyptian blue for thousands of years, and it is considered to be the first synthetic pigment.
The Egyptians never recorded their recipe for blue pigments. It was known to the Romans as caeruleum. The Roman architect Vitruvius described in “De Architectura” how it was made. Copper, sand, and natron (a substance similar to baking soda) were ground, shaped into small orbs, and heated in a furnace. He claimed that it was invented in Alexandria, however, and failed to mention the critical ingredient lime.
The Ancient Egyptians were fond of the color blue, using the same word for blue as for the eye. Blue’s reputation was earned partially because of its association with the gem known as lapis lazuli, a rare stark blue stone that would associate blue paint with wealth throughout history.
The Egyptians were able to produce synthetic blue as a result of the agricultural revolution, which provided enough stability for a non-labor workforce to arise. The pharaohs were supporters of the arts and as a result were dedicated to the advancement of pigment technology. Egyptian blue paint first appeared in the Fourth Dynasty, roughly twenty-five centuries BC. It was used from then until sometime in the fourth century AD, when the recipe was lost, and not rediscovered until the 1800s.
Without a synthetic pigment for blue paint, craftsmen began using lapis lazuli itself. The first known usage of the gem as a pigment was in Afghan temples in the sixth and seventh centuries. It made its way to China in the tenth century, and spread to India and Europe soon after. The pigment form of the gem came to be known as ultramarine, from the latin ultramarines, meaning “beyond the sea.” The name was used by Europeans because it was imported from Asia by ocean.
Ultramarine was considered one of the hardest pigments to grind by hand, and all but the most refined techniques produced inferior pale coloration. By the thirteenth century the method was improved. It was blended with resins, wax, and oils, wrapped in a cloth, and kneaded in a solution of lye. The pigment would sink to the bottom, leaving the impurities behind. The process was repeated several times, producing a lower quality pigment with each succession. The last batch was primarily a clear liquid with just a few particles of blue, and was used as a transparent, slightly tinted glaze.
Ultramarine was valued not only for the fact that it was produced from a semi-precious stone, but because of its brilliant color, and its resistance to sunlight, lime, and oil. It was used very sparingly in Europe, because by the twelfth century the cheaper azurite had become prevalent. Ultramarine was typically reserved for the highest quality blues, such as for the clothing of Mary and Jesus, with azurite used for underpainting.
Azurite was a deep blue mineral produced by the weathering of copper deposits, and it was a relatively common mineral in Europe at the time, especially in comparison with lapis lazuli. It was exported from the silver mines in Saxony, and large amounts of it were also found near Lyons, France. Azurite was considered inferior because it would age green with time. It was often confused with lapis lazuli, but could be distinguished by heating, which would turn it black. Gentle heating was occasionally used to produce a deeper blue, however. A shortage of azurite in the sixteenth century caused an increase of demand for ultramarine, raising its value even higher.
Across the ocean, the Mayans had created their own exceptionally durable synthetic pigment prior to the tenth century. The secret behind this Mayan blue paint was a mystery until recently.
In the Old World, the first synthetic blue paint since the Ancient Egyptians was finally invented in Berlin, 1706. It came to be known as Prussian blue. It is difficult to judge the accuracy of the story behind its creation, but it is said to have been discovered by a paint maker named Diesbach who was attempting produce a batch of red paint, when a contaminated ingredient led to its discovery.
A large quantity of synthetic blue paints were discovered in the following years. Cobalt blue came first in 1802, discovered by French chemist Louis Jacques Thénard. It was a cool, slightly gray blue made using salts of cobalt. Next came cerulean, discovered just three years later by Andreas Hopfner, before cobalt blue had even hit commercial production in 1807.
French painter and engraver Jean-Joseph-François Tassaert saw a blue compound form spontaneously in a kiln of lime in 1814, prompting the Societé pour l’Encouragement d’Industrie to offer a prize to the first person to artificially produce ultramarine in 1824. Jean Baptiste Guimet was successful in 1826, but he kept it a secret. Christian Gmelin discovered it independently in 1828, and published his results, causing him to take credit for the creation of the artificial ultramarine industry.
Over thirteen hundred years since ultramarine was first created, it was finally produced without lapis lazuli, and blue paint’s reputation as a color of wealth began to fade.
As recently as 2009, scientists have discovered a new kind of blue paint that is not only exceptionally durable, but environmentally benign and non-toxic.