The new issue of web mag Triple Canopy is out, and we're loving the first feature: "Thirty-six Shades of Prussian Blue." Here Joshua Cohen collects observations from historical and scholarly sources on the origins, production and uses of Prussian Blue: the world's first artificial color. It's a great read, and a wonderful insight into something we take so much for granted.

Cohen points out:

Artists in the West had no reliable blue until the early eighteenth century. Ultramarine, extracted from the blue stone called lapis lazuli, was said to have once been more expensive than gold, and Renaissance artists had to negotiate with their patrons for individual drops of blue upon receiving their commissions (ultramarine means, literally, "over the sea," because most lapis was imported from Afghanistan).

Read the entire feature here.