Ultramarine came from a single source of lapis lazuli and cost about what gold did; on a commission the pigment could run to more than the painter’s fee. Then in 1828 Guimet in France and Gmelin in Tübingen independently worked out how to make it, and by 1889 it was cheap enough that van Gogh mixed it into yellow for the greens in A Wheatfield, with Cypresses — an extravagance nobody had ever been able to afford.