THE DISCOVERY OF PRUSSIAN BLUE. I used to take the existence of the different pigments used in painting for granted. Annalisa sent me this essay by John Griswold on the Huffington Post website about the discovery of Prussian blue. Prussian blue was discovered by accident in 1704. Griswold says that previously shades of blue were based on derivatives of lapis lazuli, which was worth more than five times its weight in gold, and was consequently unavailable to any but the richest artists (or their patrons).
Prussian blue for the first time made generally available a palette of oil paints which covered the full color wheel and encouraged a great deal of exploration of advancing and receding complementary colors. Prussian blue also had the advantage that a small amount of it gave a strong tint to other colors. “Painters could now mix a much wider spectrum of colors on their palette.”
The importance of pigments is illustrated by the fact that after the French Revolution, the Republic conducted a nationally subsidized quest for new paint pigments which resulted in the discovery of cobalt blue.