The Palette/red/Grown

Madder lake

A dye from a root, precipitated onto chalk to turn it into a paint, the cool crimson that Turner could not stop using and that fades if you look at it too long.

Also called rose madder · Turkey red · manjistha · garance

Hex: #A02A3C
RGB: 160, 42, 60
Pigment index: NR9
First used: Egyptian textiles c.1500 BC; in painting from antiquity
From: India, Persia, Turkey, then the Netherlands and France

What it is

Alizarin and purpurin from the root of Rubia tinctorum, laid down on an inert base of alumina or chalk.

How it is made

This is a lake pigment, and lake-making is one of the more useful ideas in the whole craft. A dye is soluble, so it cannot be a paint. It would bleed. So you dissolve the dye, add a metal salt, and precipitate the colour onto a colourless particle. Now it is a solid, and solid means paint.

For madder: roots are dried and ground, extracted in hot water, sometimes with alum, and the dye liquor is added to an alum-and-alkali solution. Aluminium hydroxide forms in the liquid and the dye attaches to it as it does, coming out as a coloured sludge that is washed, dried and ground.

The hue depends on everything: root age, water hardness, temperature, which metal salt, how much. Turkey red, the famous brilliant madder on cotton, required a process of a dozen or more steps involving rancid olive oil, sheep dung and ox blood, took weeks, and was a closely guarded trade secret. It was the best red on cotton anybody had and it smelled like a farmyard.

Madder lake: Färberkrapp. A Rhizom der Pflanze. B Blühende Stengelspitze. 1 Blüte; 2 dieselbe im Längsschnitt; 3 Pistill; 4 Ovar im Querschnitt; 5 Frucht. A, B und 5 in natürlicher Grösse; 1, 2, 3, 4 vergrössert. — Färberkrapp. A Rhizom der Pflanze. B Blühende Stengelspitze. 1 Blüte; 2 dieselbe im Längsschnitt; 3 Pistill; 4 Ovar im Querschnitt; 5 Frucht. A, B und 5 in natürlicher Grösse; 1, 2, 3, 4 vergrössert.Franz Eugen Köhler, Köhler's Medizinal-Pflanzen/Commons/Public domain

Madder lake, Red paint made from the madder plant. Wikipedia's description, not ours.

The history

Madder is old and widespread: Indian manjistha, cloth found in Tutankhamun's tomb, Pompeii, and then a European crop grown industrially in the Netherlands and in the Avignon region, where garance was a serious agricultural economy.

In 1868 Carl Graebe and Carl Liebermann synthesised alizarin, and BASF and Perkin filed patents within a day of each other. Synthetic alizarin was purer, stronger and cheaper, and the madder-growing regions of France and the Netherlands were economically destroyed inside about fifteen years. It is the first case of a synthetic organic chemical wiping out an agricultural industry, and it is the template for what then happened to indigo.

The pigment's defect is serious and worth knowing about: natural madder lake is not lightfast. It fades, especially thinly. A considerable number of paintings now have skies that are too green and faces that are too pale because the rose madder glazed over them has gone. Turner is the standard example, several of his pictures are known to have lost their reds entirely.

Where it is used

Textiles first: Turkey red cotton, Indian chintz, British army coats before synthetic reds. In painting, glazes over a warmer red to make a cool crimson, and flesh tones.

The lake idea transfers directly to modern practice and is worth holding onto: a transparent colour and an opaque colour of the same hue behave completely differently in a layout, not just in paint. A transparent red over a warm ground glows; the same red printed flat is inert. Most design software hides this from you, and packaging on uncoated stock will remind you.

Go and look at it

Turner's watercolours with faded skies
Tate Britain, London
Kept in low light for a reason. Compare a sheet that has been exhibited with one that has not.
Turkey red printed cottons
V&A, London; National Museums Scotland, Glasgow
The Glasgow Turkey red industry was enormous. The red is still bright, which is the whole point of the process.

How it behaves

Made of: Alizarin and purpurin from the root of Rubia tinctorum, laid down on an inert base of alumina or chalk.
Opacity: Transparent. It stains rather than covers, so it can be glazed over another colour.
Lightfastness: Fugitive. It leaves. Work made with it is already less than it was.

Natural madder lake fades, particularly in thin glazes. Synthetic alizarin is better but still not first-rate.
Modern 'rose madder' on a tube is usually a quinacridone, which is permanent and a slightly different colour.
The shade shifts with the metal salt used to make the lake. Alum gives rose, tin gives a brighter scarlet.

The numbers

All derived from the hex, never typed beside it

HEX: #A02A3C; What a browser and a design file want.
RGB: 160, 42, 60; The same three numbers in base ten. Light, not ink.
HSL: 351°, 58%, 40%; Hue, saturation, lightness, how a person describes a colour.
CMYK: 0, 74, 62, 37; Arithmetic only. A real separation depends on the press, the paper and a profile.
LAB: 37, 49, 18; Perceptual. L* of 37 is how light this actually looks, which HSL gets wrong.

This hex is an approximation, and a page about pigment has to say so. Madder lake is a substance. A ground mineral scatters light from thousands of separate grains at slightly different angles, and no single sRGB value is that event. It is a flat average of a photograph of it, and the real thing is outside what a screen can emit. Use the number to specify a screen colour. Do not use it to judge the pigment.

Where it sits on the wheel

Hue 351°

Its opposite, by the diagram

#A02A3C

#2AA08E

The arithmetic opposite, 180° round in HSL. Useful, and not the same as the opposite a painter mixing pigment would name, that wheel was built for paint.

Lighter and darker

Towards white

#A02A3C

#AE4A59

#BD6A77

#D0959E

#E3BFC5

#F1DFE2

Mixing with white does not only lighten, it dulls and cools. This is why a pale tint of a brand colour so often looks chalky, and why a designed light shade beats a generated one.

Towards black

#A02A3C

#882433

#701D2A

#50151E

#300D12

#180609

Mixing with black kills the hue as it darkens. A better dark is usually the colour plus its neighbour round the wheel, which is what every painter does instead.

Can you set type on it

Handgloves

White on it
7.26:1 · AAA

Handgloves

Black on it
2.89:1 · Fails

Handgloves

It on paper
6.89:1 · AA

Handgloves

It on ink
2.52:1 · Fails

4.5:1 is the floor for body text and 3:1 for large text, by WCAG. Treat it as a minimum you may not go under rather than as a target: plenty of pairs pass at 4.6:1 and are still unpleasant to read for a page, and the checker will not tell you that.