The Secret History of Color
Aug 10, 2022
In this series, we explore the stories behind certain pigments - natural and synthetic - and how these hues, and artists’ understanding of color in general has impacted the development of art. Read the first installment, What is Color? here.
What does white mean?
Is white even a color? A scientist would probably say no, having pointed out that white light is the combination of all the wavelengths within the visible spectrum, rather than its own particular wavelength. But the artist concerned with color as a pigment would likely disagree, noting that there are many shades of white. But color or not, it undoubtedly has symbolic meaning. Black might most commonly be linked with grief, but the color of mourning in much of Asia is actually white. Its association with chastity, innocence and purity explains why Egyptian and Roman priestesses chose to wear white robes, as the Pope does today. For similar reasons, it is also the traditional choice for wedding dresses. The white uniforms of doctors, chefs and bakers are outward signifiers of health and cleanliness. It is also the wall color of many psychiatric hospitals, thanks to its supposedly calming effect. When the great Modernist architect Le Corbusier wanted one of his buildings to express clean functional simplicity, there was really only one option - paint it white.
Early White Pigments
The first white pigment was a fossilized limestone mineral called calcite, also known as chalk or ‘lime white’. It is found throughout cave paintings from the Paleolithic era. The chalk was crushed, mixed with a binder and used alongside red ochre, charcoal and bone black to create both highly stylized and remarkably naturalistic images of animals. During the Bronze Age it was also used to make vast sculptures cut into the surface of the landscape, such as the White Horse at Uffington, Oxfordshire.
A special type of lime white called ‘Bianco San Giovanni’ was first referenced in the book Il Libro dell’Arte by the 13th century Italian painter Cennino Cennini. Presumably named after the patron saint of Florence, the manufacturing process involved drying lime, crushing it finely and submerging it in water for 8 days. The resulting combination of calcium carbonate and calcium hydroxide was then formed into cakes and baked in the sun. Cennini considered the pigment essential for fresco painting, advising that Bianco San Giovanni be mixed into every other pigment to achieve light fresh tints, especially in flesh tones.
Lead white pigment is by far the most important of all whites and was being used across the lands of Ancient Egypt, Greece and Rome from around 400 BC. Its method of manufacture recorded by Pliny the Elder remained largely unchanged for over two thousand years and no doubt required a strong stomach. In small sheds, lead coils were placed in clay pots above containers of vinegar (acetic acid) and packed in with plenty of animal manure that helped generate heat and carbon dioxide. The resulting corrosive reaction caused by the fumes produced a white flakey crust (lead carbonate) on the metal’s surface that was then stripped off, dried and ground into powder. Although an invention of Ancient Greece, this is now known as the ‘stack process’ or ‘Old Dutch’ method.
The resultant pigment has a very subtle warmish pink tone and was the only white used for easel paintings (as opposed to fresco) until the 19th century. Its dense opacity offered great covering power and the possibility of thick impasto. It would be impossible to imagine the rich painterly brushwork of a Rembrandt without the unique properties of lead white. More recently, Lucien Freud’s style changed radically during the 1970s thanks to his adoption of the pigment, encouraging a shift away from the smooth and precise work of his youth towards the heavily encrusted canvases for which he became so famous.
The (great white) elephant in the room was the fact that lead is highly toxic. For centuries this wasn’t properly understood and it was all too common for people to smear their faces with the pigment from the time of Ancient Greece until the 18th century. Paler skin distinguished you socially from workers who laboured all day in the field under the sun. Unfortunately, side-effects of this cosmetic practice included spots, lesions, headaches, constipation, paralysis and, in the end, death. Assuming artists weren’t actually using it as makeup, the main danger for them (and those making the pigment) arose when the pigment was in dry powder form and the tiny particles could potentially be inhaled. Towards the end of the 19th century, scientists finally discovered that lead was poisonous and safety restrictions were increasingly placed on its manufacture. In fact, it looked like it soon might not be needed at all, as it was no longer the only game in town.
The first new white to appear was zinc oxide. Despite being known as a mineral back in the Ancient World, it was not until 1782 that chemists actually considered it for use as a white pigment. Fortuitously, vast zinc deposits were discovered in Europe at the end of the century and the paint manufacturer Windsor and Newton brought their own version to market under the name ‘Chinese White’ - still used today as a generic description. By 1834, zinc white was being used regularly for watercolour painting and has remained the preferred pigment ever since. However, it was not at all obvious that zinc white was any better than lead when it came to oil painting. On the plus side, unlike lead white, it was neither toxic nor liable to blacken in the presence of sulphur. Moreover, its cool brilliant tone could be useful for certain types of color mixing. However, zinc white was very slow drying and lacked the ‘body’ and opacity so characteristic of lead white, meaning that achieving impasto effects was much harder. When used pure and unmixed, it also forms a brittle paint film that is liable to crack.
Titanium dioxide is the most brilliant of all the whites, but despite being discovered in 1821, it took a century before a usable pigment became widely available. The first titanium white in America wasn’t manufactured until 1921. Recent investigations, however, have shown that a few painters such as Camille Pissarro appear to have been using it as early as 1900. The problem was that if bound in oil as a pure pigment, titanium dioxide forms an ugly ‘spongy’ film. The solution was to cut it with zinc oxide. The blending of these two whites happily solved their respective problems - one too spongy, one too brittle - to produce a fully reliable color with great opacity. Many artists abandoned lead white, opting instead for this brash new kid on the block. Was this the end of the road for lead white?
Lead white has not disappeared, although confusingly it goes by various names - flake white and Cremnitz white to name but two. During the 19th century, a new manufacturing process was developed using electrolysis, rather than the old Dutch stack method. On the plus side, it didn’t involve manure, but on the downside this new lead white lacked the very particular ‘stringy’ texture of its predecessor that had enabled a great variety of paint surfaces to be achieved. Nonetheless, the ease of this new process meant that soon all lead white was made this way. At the same time, the increasing dominance of titanium white looked as if it might make it redundant entirely - especially as regulations surrounding the manufacture of lead white in both America and the EU threatened to make it illegal. However, the revival of traditional figurative painting over the last two decades has led to something of a rise in demand. Just as Lucien Freud found that he couldn’t do without lead white’s unique impasto qualities, so too have many of today’s young painters. This new found interest in the past has even lead some paint makers to try their hand at producing lead white via the traditional stack method - cow dung and all.