Prussian Blue
While working in the Berlin laboratory of a prominent 18th-century alchemist, Johann Jacob Diesbach synthesized a pigment that came to be known as “Prussian blue.” Though Diesbach tried to keep his recipe secret, Prussian blue paints quickly spread around the art world.
More affordable than the lapis-based ultramarine, painters appreciated the new iron-based pigment’s ability to produce multiple tones of blue. Prussian blue is responsible for the ocean water in Katsushika Hokusai’s print Under the Wave off Kanagawa, elements in Vincent van Gogh’s The Starry Night, and Pablo Picasso’s Blue Period.
The tonal variation of Prussian blue appealed to Japanese printmakers, like Hokusai, who used it to depict entire seascapes.
Public domain