Spotlight on Colour: Cobalt Green
A semi-transparent, bright bluish-green, with a low tinting strength, Cobalt Green is extremely permanent like many pigments produced at high temperatures.
In 1780, the process for making a compound of cobalt and zinc was developed by Swedish chemist, Sven Rinmann. By exposing a mixture of cobalt and zinc to strong heat, which was then washed, the Cobalt Green pigment was ready to grind. Although available since 1835, Cobalt green pigment was not widely used until after 1860 when zinc oxide became more readily available. Arthur Church, the chemist and amateur painter, published Rinmann's process in his book, ‘The Chemistry of Paints and Painting.’ (London, 1901) He praised Cobalt Green as ‘chemically and artistically perfect.’
Cobalt Green provides an option for the painter to the more widely used Phthalo based greens or Chromium Oxide. A fast drier in oil, in water colour Cobalt Green has the characteristic of ‘granulating’ in washes, similar to Ultramarine.
Available in the Winsor & Newton Artists’ range of Oil colour, Acrylic and Watercolour.