I. PIGMENTS – c) Historical pigments
The more I learn and the more I read and the more fascinated I am by the amount of time, energy, ingenuity, effort, man has put into stealing colours from nature and appropriating them for himself: colours to adorn his body –directly on (or under!) the skin or in layers of the most colourful and sophisticated threads; to embellish his sacred spaces –from caves to cathedrals to the humble home; to represent and preserve his visions – from imaginary inner worlds to the more mundane renditions of every day life and beauty. For whatever purpose, it is obvious by traces of their passage that humans have wanted, perhaps needed, colour in their lives in all places and at all times. And have gone to extreme lengths and expenses to acquire it.
(You might wish to read a post I’ve written about that: The oldest profession in the world?)
The first pigments of men were inorganic minerals found in the soils:
- clays and oxides offering them a palette ranging from browns to reds to yellows, with, in some places, some natural violets or greens
- chalks and crushed bones providing white
- charred wood or bones adding black
But, as long ago as 8 000BC, Egyptian artists discovered how to process many more natural minerals, animal products or vegetable matter into useful and more or less stable colorants. As is the case even now, pigment manufacture in Antiquity was a by product of more daily necessities: glazing, dying, soap and glass making… but there is no question that the Egyptians had a genuine command of chemistry. Around 3500B.C., they discovered how to win cooper from its ores and take the leap from physical to chemical manufacturing.
- Copper ores malachite (green) and azurite (blue)
- Arsenic sulfides orpiment (yellow) and realgar (orange)
- Reds from cinnabar and iron (a mercury ore)
- Lead white which became such an important pigment for the Greeks and Romans was probably already in use in Egypt since lead was liberated from its ores as early as the third millennium B.C.
- There was also the gorgeous Egyptian blue or frit –used above– which is found as early as 2 500 BC… this is the oldest synthetic pigment and a recipe lost for a long time after. Just to give you an idea of the complexity of it there goes: 1 part lime (calcium oxide), one part copper oxide and 4 four parts quartz (silica) were blended together. These raw ingredients are minerals: chalk or limestone, a copper mineral as malachite and sand. Fired in a kiln between 800 to 900 degrees celsius (and this temperature is crucial so we can deduct from that that the Egyptians had found ways to master that art too) it produced a brittle blue material which could be ground to a fine pigment. This whole operation shows highly specialized knowledge combined with practical mastery.
Whether their invention or not, Egyptian dyers also enjoyed the deep red of kermes –a little insect. Turning this dye into a usable carmine lake pigment is one of the tour de force of early chemistry but worth the effort obviously to obtain the beautiful carmin red. One they repeated with the deep red even purplish root of the madder plant.
Although the Greeks had a fine reputation as painters and it is presumed Greek painters were at work both on the Pompei frescoes and in the gorgeous encaustic Fayum portraits, there are virtually no certified Greek paintings remaining. Certainly though it was around that time that White Lead began to be extensively used even as make up under the name of ceruse (by the way… that’s not a good idea at all!) Probably the earliest artificial pigment still in use today (although forbidden in many countries now because of it lead content), this pigment, also called Flake white or Creminitz white, is produced by leaving for a few weeks lead in thin slices with vinegar, under animal manure which keeps it warm. Microscopic little white crystals then form on the lead and they can be picked like little flowers.
From exposure to fire white lead can be transformed into red lead. That pigment was also known and used lavishly in Oriental art although it is then called lead cinnabar.
During the next centuries, some processes were forgotten and other improved as, on the whole, more and more sophisticated ways of processing materials were devised. Iron oxides were mined extensively and processed by heating, water washing and other means into a range of red, yellow, green and dull purples. More complex processing resulted in producing smalt, king’s yellow and the delightful ultramarine blue from lapis lazuli. On the organic side: resinous materials produced reddish dyes (better know as the exciting dragon’s blood), while vegetable and animals materials were turned into ever more gorgeous
reds (the sepias, bistres, and cochineals),
yellows (think turmeric, saffron, Indian yellow, quercitron),
blues (thanks to indigo)
and greens (sap green).
Some would argue however that the most central technological innovation of medieval painting was the synthesis of vermillion… a truly alchemical affair! A pigment as costly as gold for a long time, it was first used sparingly, until more sophisticated forms of manufacture made it affordable. The Dutch dry method, in which mercury and sulfur was combined to create a black form of mercury sulfide that was then pulverized and sublimated by strong heating and converted into red vermilion was the first step. Later came a less laborious and costly wet process with ammonium…. what would you not do for a good Vermilion?
As you go through older books or historical pigment descriptions, don’t attach yourself tooooo much to names however as most colours ended over time with quite a range of names here and there on the globe whereas some names served for a variety of hues!
Here’s one fun example of that: Caput mortuum (or mortem), also known as Cardinal purple. This name was given to a purple variety of haematite iron oxide pigment. It was a very popular colour for painting the robes of religious figures and important personages. It may have come from the alchemical usage, since iron oxide (rust) is the useless residue of oxidization. It was originally a byproduct of sulfuric acid manufacture during the 17th & 18th centuries, and was possibly an early form of the copperas process used for the manufacture of Venetian red and copperas red. But Caput mortuum is also sometimes used as an alternative name for Mummy brown, a pigment that was originally made in the 16th and 17th centuries from ground-up mummies, and whose use was discontinued in the 19th century… when artists became aware of its ingredients!
Still many pigments were discovered and had to be abandoned –usually as time would prove them not lightfast enough– or used with great caution as they would alter chemically other colours around or mixed with them.
Much of these improvements were no doubt due to years of trial and error and recipes passed on like secrets from master to apprentices, monk to monk, calligrapher to calligrapher, miniature artist to miniature artist. Supports evolved too and with them the concept of hanging art on a wall –rather than painting the wall itself– was introduced. Canvas, then paper made the transport of artworks ever more easy and versatile. Art could change hands and countries as it never had before and, with that, knowledge was passed on too.
A historical palette at a glance…
The chart of Rublev colours below –a small American brand which strictly sticks to the historical pigments– is what the painter had at its disposal before 1704 when the earliest synthetic mineral pigment, Prussian blue, was invented by chemistry. (If you exclude the Ultramarine made from the synthetic pigment which replaces the real deal, ie lapis lazuli, far too expensive). I think you can appreciate at a glance here that although many many masterpieces were painted before that time, not that many pigments were in fact available…
click if you want to know more about Modern pigments
click if you want to know more about What is a pigment?
click if you want to know more about Colours and families of pigments
click if you want to know more about Binders and making your own paint