The Story of Ultramarine from the Silk Road to Renoir: The Chemistry of Color

How did ultramarine go from being more expensive than gold to one of the cheapest pigments for artists? Follow the journey of this vibrant blue color, ultramarine, one of the most celebrated and sought-after pigments in art. Joanna Russell from our Scientific Department looks at the use of this blue in 'The Wilton Diptych' and Renoir's 'Umbrellas'.