Hokusai's Great Wave Was Painted in a New German Pigment

Katsushika Hokusai was about seventy when he started the print series Thirty-Six Views of Mount Fuji in 1830. The most famous image in it, Under the Wave off Kanagawa — the curling claw most people just call "The Great Wave" — owes its presence to a colour Hokusai's grandfather could not have bought.

The pigment is Prussian Blue, the deep, faintly greenish navy that paints the wave, the sky, and the outlines of the boats. It was synthesised by accident in Berlin around 1706 by the colour-maker Johann Jacob Diesbach, who was trying to make a red. The compound — iron ferrocyanide — was the first modern synthetic pigment and the first colour-fast, lightfast blue cheap enough for ordinary use.

For a century it stayed mostly European. Traditional Japanese prints used indigo for blue, which fades quickly, or natural ultramarine, which was prohibitively expensive. Both Dutch traders at the artificial island of Dejima off Nagasaki and Chinese ships brought small quantities of Prussian Blue into Japan from the late 18th century, but it was costly until a domestic and Chinese supply expanded in the 1820s.

That price drop is why ukiyo-e from the 1830s onward looks blue. Hokusai's contemporary Hiroshige used the same pigment to similar dramatic effect in Famous Views of the Eastern Capital. Publishers commissioned series printed mostly in the new colour and marketed them as aizuri-e, blue-printed pictures.

The wave is iconic enough that its blueness reads as inevitable. It was, in fact, a recent import.