Before the tube
Until the middle of the nineteenth century, a painter who wanted blue could not simply buy it. They bought a stone, a cake or a twist of paper from an apothecary, and they — or more often an apprentice — ground it on a slab of porphyry with a muller, worked in oil or egg or gum until it would hold, and used it before it skinned over. Colour was a material before it was an idea, and every material came from somewhere: a mountain valley in Afghanistan, a cactus farm in Oaxaca, a dye works in Tyre that you could smell from the harbour.
The tin tube changed that. In 1841 an American portrait painter living in London, John Goffe Rand, patented a collapsible metal tube closed with a screw cap. Colourmen filled it; painters carried it out of doors. Renoir is supposed to have said that without paint in tubes there would have been no Impressionism — a tidy line, probably polished in the retelling, and still mostly true.
This guide goes back behind the tube. Its thirteen entries are not the most important pigments in history so much as the most revealing: each is a short account of a supply chain. Some were dug, some grown, some harvested from animals, and some cooked in a workshop, occasionally by mistake. Several poisoned the people who made them. One was made out of people.
Use the index to narrow them by source or hue, open any entry for its history, or open its plate for a large drawdown. Tick Compare on the ones you want side by side, and the table that follows narrows to match.
The index
Thirteen entries, numbered in the order the ledger keeps them. Each swatch is a drawdown: full strength on the left, thinning to a film on the right, crossed by a black bar that shows how well the paint hides what lies beneath. In the narrow swatch book, opening an entry’s history widens it across the row.
-
Ultramarine
01 · Lapis lazuli · Afghanistan
The blue that cost more than gold, washed out of a semi-precious stone.
History
Lapis from Sar-i Sang, in the Kokcha valley of north-east Afghanistan, travelled west for millennia before anyone painted with it; the earliest known painted use is in the sixth- and seventh-century cave murals at Bamiyan. Crushed lapis gives only a greyish blue. The pigment is extracted by kneading the powder into a dough of resin, wax and oil and working it under lye: the blue washes out, the grey stays in the dough. Renaissance contracts specified it by the ounce for the Virgin’s robe. A French prize offered in 1824 for a synthetic version was won by Jean-Baptiste Guimet in 1828, and the scarcity ended within a generation.
Ultramarine
Na₇Al₆Si₆O₂₄S₃
Semi-opaque: over the black bar it deepens to violet-black rather than vanishing. Its tints stay blue all the way to white.
-
Egyptian blue
02 · Calcium copper silicate · Egypt
The first colour anyone manufactured, then forgotten for a thousand years.
History
Made by firing sand, lime, copper ore or bronze scrap and natron together at around 850–1000 °C, it was in use in Egypt by the middle of the third millennium BCE and spread around the Mediterranean; Vitruvius gives a recipe under the name caeruleum. After the Roman period the knowledge faded and was lost. In this century conservators found that it glows in the near-infrared when lit with ordinary light, so a camera can find traces too faint for the eye — including on the Parthenon frieze.
Egyptian blue
CaCuSi₄O₁₀
Coarse crystals that granulate — the speckle in the drawdown. Ground finer, it pales toward the upper steps of the tint ladder.
-
Prussian blue
03 · Iron ferrocyanide · Berlin
A red that went wrong in a Berlin workshop around 1705.
History
The colour-maker Johann Jacob Diesbach was making a cochineal lake with potash borrowed from the alchemist Johann Konrad Dippel. It had been contaminated with Dippel’s animal oil, distilled from blood and bone, and the batch came out an intense blue. It was the first modern synthetic pigment, a fraction of the price of ultramarine, and it reached Japan as “Berlin blue” in time for Hokusai’s Great Wave. It fades in strong light and recovers in the dark — and, unexpectedly, it is an antidote: capsules of it bind radioactive caesium and thallium in the gut.
Prussian blue
Fe₄[Fe(CN)₆]₃
Transparent and enormously strong. The black bar barely changes, yet a trace in white still reads as blue far up the ladder.
-
Indigo
04 · Indigofera tinctoria · India
A dye from fermented leaves, which painters borrowed and rarely kept.
History
Leaves of Indigofera, or of woad in Europe, are steeped and fermented until a colourless precursor oxidises to blue indigotin, which settles as a sludge and dries into cakes. The oldest known indigo-dyed cloth, from Huaca Prieta in Peru, is about six thousand years old. As a paint it fades badly. The Maya fixed this by heating it with a clay, palygorskite, that locks the molecule into its channels: Maya blue has survived centuries of jungle damp on the walls at Bonampak.
Indigo
C₁₆H₁₀N₂O₂
Dark and transparent; alone it reads almost black. The colour lives mid-ladder, where it turns a cool slate.
-
Vermilion
05 · Mercury sulfide · Almadén
The hottest red in the box, from mines worked by convicts.
History
Natural vermilion is ground cinnabar, and the great source of the Roman world was Almadén in Spain, which was still producing mercury in the twenty-first century. From the Middle Ages most was made instead by the “dry process”: mercury heated with sulfur until a black sulfide forms, then sublimed red. It is dense, opaque and brilliant, and unstable — in light, especially with chlorides, the surface can darken to grey-black, as happened to some of the red walls of Pompeii.
Vermilion
HgS
Hides the black bar almost completely. Its tints go to salmon quickly: vermilion is a masstone colour.
-
Madder lake
06 · Rubia tinctorum · Anatolia & Holland
A root dye fixed onto a mineral — and the first natural colour beaten by a laboratory.
History
Madder roots hold alizarin and purpurin. Dissolved and then precipitated with alum, the dye clings to the forming alumina and becomes a solid, transparent “lake” that painters glazed in thin layers over a lighter ground. Holland and France grew it on an industrial scale. In 1868 Carl Graebe and Carl Liebermann synthesised alizarin from coal tar, the first natural dye made in a laboratory, and within a decade the madder fields were ploughed up.
Madder lake
Alizarin, C₁₄H₈O₄, on alumina
Almost no hiding power — the bar shows straight through. Its beauty is in thin glazes, which the right of the drawdown imitates.
-
Carmine
07 · Cochineal insect · Oaxaca
Seventy thousand insects to the pound, and New Spain’s second fortune after silver.
History
Cochineal are scale insects living on prickly-pear cactus; the females are brushed off, killed and dried. Mexican and Andean dyers farmed them for centuries before the Spanish arrived, and from the 1520s the dried insects crossed the Atlantic in such volume that they became New Spain’s most valuable export after silver. Laked onto alum, carminic acid gives a cool crimson that is tragically fugitive in light. It is still with us, as the food colouring E120.
Carmine
Carminic acid, C₂₂H₂₀O₁₃, on alumina
Cool and transparent. The tint ladder holds some of the purest pinks available before 1900 — exactly the ones that faded first.
-
Tyrian purple
08 · Murex snails · Tyre
Twelve thousand snails for a gram and a half of colour.
History
The dye comes from a gland of several Mediterranean murex snails; exposed to air and light, the secretion turns from yellow through green to purple. Phoenician Tyre made it the colour of power, Roman law limited who could wear it, and the dye works were notorious for their stench. When the chemist Paul Friedländer identified the molecule in 1909 he needed some 12,000 snails to extract 1.4 grams. It was above all a dye; as a paint it survives in only a handful of ancient works.
Tyrian purple
6,6′-Dibromoindigo, C₁₆H₈Br₂N₂O₂
A red-violet of middling transparency. The paler steps are nearer what most Romans wore: cheaper, diluted, still purple.
-
Yellow ochre
09 · Iron oxyhydroxide · Everywhere
The oldest pigment there is, and still one of the most reliable.
History
Ochre is clay coloured by goethite, and it occurs almost everywhere. At Blombos Cave in South Africa, people mixed it with bone and charcoal in abalone shells about 100,000 years ago — the oldest known paint workshop. Heat yellow ochre and it loses water and turns red: quite possibly the first deliberate chemical change in human history. It does not fade, does not react with its neighbours, and costs almost nothing.
Yellow ochre
α-FeO(OH) in clay
Opaque, earthy, faintly granular. Tints go to warm cream and shades to olive — the hidden base of many landscape greens.
-
Indian yellow
10 · Magnesium euxanthate · Bihar
A luminous yellow with a story nobody has managed to confirm.
History
It reached Europe as hard, foul-smelling balls called purree. In 1883 T. N. Mukharji reported that it was made at Mirzapur, near Monghyr in Bihar, from the urine of cattle fed only on mango leaves. No second witness, and no law forbidding the practice, has ever been found. The chemistry fits — euxanthic acid is a product of animal metabolism — but the rest is unproven. Whatever its source, it vanished from the market early in the twentieth century.
Indian yellow
Mg(C₁₉H₁₅O₁₁)₂ · 5H₂O
Transparent and glowing. Laid thin over white it has the warmth that made it a staple of Mughal and Rajput painting.
-
Scheele’s green
11 · Copper arsenite · Sweden
Cheap, brilliant, and in the wallpaper.
History
Carl Wilhelm Scheele, who also discovered oxygen independently of Priestley, published it in 1775. It was cheap and vivid, and Europe used it for everything: wallpaper, dresses, artificial flowers, sweets. In damp rooms, moulds feeding on the paste could release arsenic as a gas. Napoleon’s rooms on St Helena were papered in a green of this kind and arsenic was later found in his hair; whether one caused the other is still argued. Its successor, emerald green, was brighter and no safer.
Scheele’s green
CuHAsO₃
Fairly opaque and yellow-leaning. Shaded with black it collapses to a dull olive; in sulfurous air it darkens on its own.
-
Lead white
12 · Basic lead carbonate · Holland
The white of European painting, made in a pile of dung.
History
In the “stack” or Dutch process, coils of lead sat in clay pots over a little vinegar, buried in tiers under tan bark or horse dung. Fermentation gave off heat and carbon dioxide, the acid vapour corroded the metal, and after weeks the stacks were broken down and the white crust scraped away. It made a supple, quick-drying film that held a brushmark, and it is dense to X-rays — which is why radiographs show the changes painters made underneath. The scrapers got lead colic; sometimes, so did the painters.
Lead white
2PbCO₃ · Pb(OH)₂
Opaque, and warm rather than blue-white. Its shade ladder runs through the cool greys of Dutch interiors.
-
Mummy brown
13 · Bitumen & human remains · Egypt
Exactly what it says.
History
Ground mummy was sold by European apothecaries as medicine from the Middle Ages; by the sixteenth century colourmen were selling it too, as a transparent brown for glazing shadows. Its quality varied with whatever bitumen, resin and remains it held, and it cracked and wandered in the paint film. Rudyard Kipling remembered his uncle, Edward Burne-Jones, learning what it was made of and solemnly burying his tube in the garden. In 1964 the London colourman C. Roberson said it had run out, and could not find another mummy.
Mummy brown
Bitumen, myrrh, resins, bone
Warm and semi-transparent. Every batch differed, so this drawdown is an average of descriptions, not of any one tube.
Showing of 13 pigments
Side by side
Each pigment at full strength, then let down in six steps of fifteen per cent. Lead white shows how a colour behaves as a tint; bone black, how it shades; aged linseed varnish, why so many old blue skies now read as green.
| Pigment | Let-down, 0–90% | Hiding | Lightfastness | Hazard | First use |
|---|---|---|---|---|---|
| Ultramarine | Semi-opaque | Excellent; acid-sensitive | None | 6th c. CE | |
| Egyptian blue | Semi-opaque | Excellent | None | c. 2600 BCE | |
| Prussian blue | Transparent | Good; recovers in dark | Low | c. 1705 | |
| Indigo | Transparent | Poor | None | Antiquity | |
| Vermilion | Opaque | Fair; may blacken | Mercury | Antiquity | |
| Madder lake | Transparent | Fair | None | Antiquity | |
| Carmine | Transparent | Poor | None | 1520s in Europe | |
| Tyrian purple | Semi-transparent | Good | None | Bronze Age | |
| Yellow ochre | Opaque | Excellent | None | Palaeolithic | |
| Indian yellow | Transparent | Fair | None | c. 1500 | |
| Scheele’s green | Semi-opaque | Fair; darkens | Arsenic | 1775 | |
| Lead white | Opaque | Excellent; darkens with sulfur | Lead | Antiquity | |
| Mummy brown | Semi-transparent | Poor | None | 16th c. | |
| of 13 shown. Tick Compare on any card in the index to narrow this table; untick them all to see every pigment again. | |||||
Four ways to make a colour
Every entry in the index was made one of four ways. The method set the price, the stability and, often, the human cost.
DigMinerals & earths
Earths and minerals are the oldest and steadiest pigments: ochres, umbers, green earth, cinnabar, malachite, azurite, lapis. Most need only washing, sifting and grinding, though grinding is a trap — many minerals pale as their particles shrink, so coarse azurite is a deep blue and fine azurite is sky. Their weakness is supply. A colour from one valley in Afghanistan has a price set by roads, wars and whoever controls both.
GrowPlants & lakes
Plants give dyes, which dissolve, rather than pigments, which do not. The trick that turns one into the other is the lake: dissolve the dye, add alum and an alkali, and the colour precipitates onto the white mineral that forms, like ink soaking into chalk. Madder, weld, brazilwood and indigo were all used this way. Lakes are transparent, glowing and, almost without exception, fugitive.
HarvestInsects, snails & worse
Animals supplied some of the most expensive colours ever sold: cochineal and kermes insects, murex snails, the resin of the lac insect. All need enormous numbers of creatures for small amounts of colour, which made them stores of value as much as materials. They also produced the strangest supply chains in this guide, two of which — Indian yellow and mummy brown — read more like rumour than trade.
CookKilns, vats & accidents
Synthesis is older than chemistry. Egyptian blue was being fired in kilns four and a half thousand years ago, and lead white was made by corroding metal with vinegar long before anyone knew what an acid was. What changed in the eighteenth century was intent: Prussian blue was an accident, but Scheele’s green was a result, and by 1868 a chemist could set out to make a natural dye and succeed. The price of colour began to fall, and kept falling until a tube of ultramarine cost less than lunch.
What the ledger leaves out
Thirteen is a small number. This guide leaves out azurite and malachite, smalt and Naples yellow, verdigris, bone black and gamboge, each with a history as tangled as anything here. It also leaves out most of the people: the convicts at Almadén, the families who brushed cochineal from cactus pads, the stack workers with lead in their gums. Pigment histories are usually told from the studio, because the studio is where the receipts were kept.
Look at a painting with that in mind and the surface changes. A Virgin’s robe is a price negotiated in a contract; a green dress is a risk; a deep, warm shadow might be somebody’s ancestor. Colour was never free, and for most of history it was not even cheap.