Purple Haze

PG18—Synthetic mineral - hydrated chromium oxide, discovered 1838. A 19th-century arrival, viridian became the transparent green of the Impressionists - Cézanne’s cool greens and Monet’s water rely on it. The classic transparent green - stable, granulating, and the backbone of natural landscape greens.

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.

PO73—DPP Orange. Synthetic organic. A vivid, very lightfast orange introduced in the 1980s.