Imperial Purple

PB29—Synthetic - a replica of the lapis lazuli mineral, first made commercially by Guimet in 1828. Natural ultramarine, ground from Afghan lapis, was the most prized pigment of the Renaissance - reserved for the Virgin’s robes in Giotto, Titian and Vermeer. After 1828 the synthetic version democratised that blue; the Impressionists built their skies and shadows on it. From the most expensive pigment in the medieval palette to a staple of every painter’s box - ultramarine remains the definitive warm, stable blue.

PV19—Synthetic organic - quinacridone (violet crystal form). No Old Master could paint a permanent violet - quinacridone violet is a 20th-century gift, letting painters build luminous purples that will not fade. A modern, permanent violet - transparent and strong, ideal for glazes and lively tints.