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In ancient Egypt the sky was a gleaming blue, the sacred lotuses had blue petals, the pharaoh’s battle crown was blue, beautiful women wore chokers made of blue stone, and, above all, the life-giving Nile was blue. The ancient Egyptians needed azure pigment to portray these essential elements of life within their sacred art, but the only natural blue pigments were from turquoise and lapis lazuli—semi-precious stones which were rare and expensive. To provide a sufficient supply of blue pigment for painting, jewelry, and sculpture, the Egyptians therefore invented the first synthetic pigment which today is appropriately known as “Egyptian blue” (well, it is also appropriately known as calcium copper silicate–CaCuSi4O10 or CaO·CuO·4SiO2—but I’m going to keep calling it Egyptian blue).
Egyptian blue was synthesized in the 4th Dynasty (c.2575-2467 BC) when the newly created pigment was first used to color limestone sculptures, beads, and cylinder seals. Its use became more prevalent in the Middle Kingdom, and then increased again during the New Kingdom when blue was used for the production of numerous everyday objects. Throughout the Hellenic and Roman age, Egyptian blue was a mainstay of the nascent chemical industry, and it found its way into all sorts of art, jewelry, crafts, and artisan wares. Then, in the fourth century the secret of its manufacture was lost. Only in the beginning of the nineteenth century did interest revive as the English and French pioneers of the chemical trade rushed to synthesize useful compounds. As one might surmise from the fact that the manufacturing process was lost for a millennium and a half, the method to make Egyptian blue is surprisingly involved. Citing a British Museum publication, Wikipedia describes it thus:
Several experiments have been carried out by scientists and archaeologists interested in analyzing the composition of Egyptian blue and the techniques used to manufacture it. It is now generally regarded as a multi-phase material that was produced by heating together quartz sand, a copper compound, calcium carbonate, and a small amount of an alkali (plantash or natron) at temperatures ranging between 800–1000 °C (depending on the amount of alkali used) for several hours. The result is cuprorivaite or Egyptian blue, carbon dioxide and water vapor…
The Egyptians were clearly people who took their pigments seriously, and thankfully so–the blue tints they crafted have lasted for thousands of years (and helped us find our way to synthesized pigments). It is strange to think of the subtle ways that the Nile still flows through our lives.
In the spring of 1974 a group of farmers digging a well in Shaanxi China about one and a half kilometers (1 mile) north of Mount Li stumbled into an amazing find. A life-sized army of terracotta soldiers numbering over 8000 was entombed in the immense necropolis of Qin Shi Huang, the first emperor of China who lived from 259 BC – 210 BC. However the story of the despotic Qin Shi Huang (one of history’s most remarkable figures) and his extravagant mausoleum will have to wait. This post is not about the cruel emperor or his terracotta army, but is rather about the colors found on the terracotta figures, which were originally lacquered with a rainbow of bright colors– pink, red, green, blue, black, brown, white, and lilac. One of the pigments discovered by archaeologists was Han purple, a manufactured pigment which was in use in China from about 1200 BC to 220 AD. The secret to making Han purple was lost in antiquity and could not be rediscovered until modern spectroscopy helped chemists rediscover the materials used.
Many scholars believe that Han purple was accidentally discovered by Taoist alchemists seeking to create synthetic jade. The compound was a barium copper silicate which was fired for long periods of time at temperatures around 900-1000 °C. The compound was probably produced in kilns north of the city of Xian (which was once known as Chang’an and was the capital city of China during the Zhou, Qin, Han, Sui, and Tang dynasties).
Han Blue was a dark bluish purple/indigo. It became more purplish over time as the barium copper silicate deteriorated and red copper oxides were formed. The pigment was used for beads, ceramic vessels, paintings, and for octagonal pigment sticks (which may have had a ceremonial value in their own right).
Han purple had a very similar companion compound–Han blue—which was also a barium copper silicate. Because of certain quirks of chemistry, Han blue was more lightfast than than Han purple and had fungicidal properties to boot. This allowed Han blue to last for the long centuries, whereas Han purple is now known mostly from faded traces. Han purple was not fungicidal and compounds (namely oxalates) produced by certain long-lived lichen caused the pigment to turn into light blue powder.
One of the most useful colors in an artist’s palette is one of the last colors anyone else would think. Only its spooky name would incline your attention towards it. Caput mortuum, which means dead head or death head, is made of haematite–iron oxide (in fact there are several extremely similar colors made of the same pigment but with slightly different hues and names–particularly mars violet and Indian red—but we will stick to talking about caput mortuum because that’s the variation I use). This unpromising rust color possesses a protean mutability–it could be red, brown, orange, or violet depending on the context. Although it can stand on its own as a focus of attention, caput mortuum is very easy to paint into a network of subtle shadows: many painters use it for shadowed flesh or as land cast in darkness (after all a person’s flesh and the red clay of a landscape both take their ruddiness from iron).
Though not a flashy color, caput mortuum has a dignity and a beauty to it. In the middle ages and Renaissance, painters used it to paint the robes and clothing of eminent monastic religious figures and of patrons & donors (ie the people actually paying for the painting). Oftentimes when looking at a religious painting, a viewer will notice that Jesus, Mary, and Saint Peter–resplendent in gold, white, blue, and red—are joined by an unknown pair of merchants wearing caput mortuum. These two often have the most realistic and beautifully painted faces in the painting–it is difficult to say what Jesus really looked like but even the most money grubbing burgher knows his own face!
Although there is something somber about the deep color of caput mortuum, its name does not come from an obvious association with blood and corpses. In addition to meaning “dead head” the Latin phrase also means “worthless remains” and it was used by alchemists to describe the inert residue left over from a chemical reaction. Apparently this by-product was often a rusty violet color. Alchemists used a (very) stylized skull to denote the oxidized left-overs.
However it’s more evocative to imagine the pigment being named after a death’s head. The concept lends art a much needed touch of operatic dark magic.
I wrote earlier about sepia ink, the beautiful drawing and writing medium used in the Mediterranean for thousands of years which was obtained from the ink sacks of cuttlefish. Was sepia ink also used by the great northern masters for their sketches? Not at all: there was an altogether different source of the beautiful smoky brown inks used by Brueghel, Durer, Lorraine, and Rembrandt (as well as most other German, French, Flemish, Dutch, and English artists) when they sketched from life. The name of the transparent shadowy brown pigment with yellow undertones was bistre and its source was not a mollusk but rather a tree. Bistre was made with the soot left over from burning beechwood. The beechwood ash was boiled with water to produce a cheap and superior drawing pigment. Although steel and copper nibs certainly existed, most masters probably sketched with simple reed pens or goose quills (waterfowl were generally agreed to provide the best drawing quills and geese were most readily available).
Since I have a great fondness for both beech trees, reeds, and geese, it cheers me to think that the great drawings of the old masters were produced with such humble materials. Unfortunately there is no way to set out any sort of comprehensive collection of bistre drawings: the medium was more universally used then anything other than carbon black. Even a little sampler would involve a wildly eclectic mixture of works from all sorts of drafstmen from wildly different ages and schools. So, instead I am showing three little Rembrandt drawings to represent bistre. I don’t write as much about Rembrandt as I do about other lesser artists (i.e. the rest) because my feelings about his ineffable works are hard to characterize. The “Lines and Color” blogs summarizes the scope of Rembrandt’s drawings:
Over 1,400 of his drawings survive, conservatively estimated at less than half of what he produced. (For most great artists we’re lucky to have a few dozen. For Vermeer and Franz Hals we have none.) Also unlike most of the great masters, the majority of Rembrandt’s drawings were not done as preparation for paintings, and very few were signed as pieces to be presented to friends or patrons. Most of his enormous outpouring of drawings were apparently done for himself, as visual record of his life and experience or simply for the joy in the act of drawing.
The multitude of subjects encompassed in 1,400 drawings provides a comprehensive overview of life in seventeenth century Holland (which was one of the focal points of the first wave of true globalism). Out of the murky brown ink washes emerge an endless parade of long-vanished people, places, and things. The figures work, play, and struggle in cities manufactured of hasty brown lines under brown clouds beside an ink wash ocean (over which inky ships carried the spices of the old world and the furs from the new). Magicians scheme, children squall, and captive lions recline. It is my favorite alchemy. Rembrandt gives us an entire world crafted out of water and beechwood ash.
Since prehistory, cinnabar (mercury sulfide) has been sought after for its brilliant red-orange hue. Crushed into a pigment, this mineral becomes vermilion, and it is one of history’s great colors. The bright red-orange of vermilion is unmistakable and takes pride of place in many—maybe most–of the great paintings created prior to the introduction of modern cadmium paints. The villa of the mysteries in Pompeii was painted with vermilion. Medieval illuminators made extensive use of vermillion to color the bibles, codexes, and prayer books of the times.
In the 8th century, Chinese chemists discovered how to artificially synthesize cinnabar. The alchemists of medieval Europe mastered this trick later in the 12th century (after which both painting and chemistry made great strides forward). The brightest reds in the great masterpieces of Renaissance art are vermillion as are the brightest reds in the masterpieces of Baroque, Rococo, and Romantic painting.
Because of its high mercury content cinnabar is very toxic to humans. People affected by mercury poisoning develop tremors, violent mood swings, and tunnel vision. They lose first their hearing, then their eyesight, and ultimately their sanity and lives. The Romans knew these problems were associated with cinnabar mining and so they sent criminals and war slaves to man the mines of Spain and Slovenia. Such wretches had an average life span of only three years.
Because of its magnificent red color, and because it could be refined to yield liquid mercury (which was regarded as a magical regent of life) cinnabar was thought to be one of the keys to the fabled elixir of life. Taoist charlatans and magicians made extensive use of raw cinnabar for allegedly rejuvenating cups, trinkets, and potions. Contrasting this paragraph with the one prior to it yields an obvious irony: the magical life giving elixirs quaffed by Taoist mystics were toxic. Many Chinese emperors, aristocrats, and elites probably greatly shortened their life by becoming too enamored with the deadly beauty of vermilion