Madder, indigo, and why the old dyes came back

Before 1856 every colour in a carpet came out of a plant, an insect or a mineral. Madder root gave every red from brick to rose depending on the mordant and the water. Indigo gave blue and, over a yellow of weld or vine leaf, green. Walnut husk and oak gall gave the browns and blacks.

Then came aniline dyes: cheap, brilliant, and available in colours no plant could produce. Within twenty years they had spread through Persia and Anatolia, and within another twenty the carpets made with them had turned grey and brown in the sun and bled into each other at the first wash. Persia banned aniline imports in 1903, with the shah threatening to cut off the hands of dyers caught using them.

An entire generation of carpets is worth a fraction of what it should be, because of a dye that looked wonderful for a decade.

How natural dye ages

It fades — but it fades towards a related colour rather than away from colour altogether. Madder red goes softly to terracotta and then to salmon. Indigo lightens to a dusty mid-blue. The two remain in conversation with each other, which is why a hundred-year-old carpet looks harmonious rather than washed out.

The other effect is abrash: visible bands of slightly different tone running across the field, where one dye lot ran out and the next was not quite identical. Dealers once tried to hide it. It is now understood as a signature of a hand-dyed, hand-woven piece, and a carpet with none at all invites the question of what it was dyed with.

Where things stand now

Good modern chrome dyes are genuinely lightfast and hold their colour for decades — the disaster of the 1880s is not being repeated. But they hold it flatly. Natural dye gives a colour that shifts slightly with the angle of the light, because the fibre has taken it unevenly at a microscopic level. Nine of the workshops we buy from dye naturally by choice, and pay for it in time.