Spotlight on colour: Prussian Blue


An intense transparent blue pigment, Prussian Blue has a high tinting strength and produces a range of hues from the palest tint to a deep blackish-blue. It is also known as Berlin Blue, Parisian Blue, Chinese Blue and Iron Blue.

Famous for being amongst the first synthetic pigments ever created, Prussian Blue was discovered purely by chance through a lucky accident. In c.1704, the German colour-maker Diesbach was creating a red lake pigment to use as a dye, using iron sulphate and potash. On this occasion, the potash was contaminated with impurities (animal oil) and instead of a bright red, Diesbach produced a purple, which when concentrated, became a deep blue pigment. In this way, the first synthetic blue pigment, iron ferriferrocyanide was created. Diesbach quickly realised the importance of his discovery as the pigment provided a new alternative to the only permanent blue pigment available, Ultramarine (Lapiz Lazuli), which was extortionately expensive as it was mined in limited amounts in Afghanistan.

By 1710 Prussian Blue was being used by many artists in the Prussian Court, hence its name. The first painting recorded using Prussian Blue is the ‘Entombment of Christ’ by Pieter van der Werff in 1709. The use of the pigment quickly spread through Europe in watercolour and oil colour, used by artists such as Antoine Watteau and Jean-Baptiste Pater. It then spread globally as far as Japan, where it was used for Hokusai’s ‘The Great Wave off Kanagawa’ woodblock painting. Since then, Prussian Blue has featured in the palettes of artists such as Monet, Constable, Gainsborough, L.S. Lowry, as one of the colours in his famed limited palette and Picasso in his famous Blue Period.