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Technology:
Paint Manufacture and Testing
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The North London Colour Works at Kentish Town 1864 built a year before the death of William Winsor. The Works' mills were designed by Henry Charles Newton to simulate the grinding of colours by hand. He also added an extensive chemical laboratory so that he could make or process practically all the pigments he needed, without having to rely on the open market for them.
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It not only manufactured chemical colours, but also processed the natural earths and exotic pigments such as Indian yellow, gamboge and genuine ultramarine from lapis lazuli as well as the lakes and madders. |
Several distinguished artists wrote to the Times in the late 1880s criticizing artists' colourmen for selling impermanent and fugitive colours, and accusing them of keeping the composition of their colours secret. This correspondence lead to a detailed investigation into the action of light on watercolours researched by Dr. William J. Russell and Capt., later Sir William, Abney, the authority on colour measurement, in 1888.
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The findings, published in a 'Blue book' were reassuring, and Winsor & Newton made history by being the first colourmen to publish permanence ratings for their colours and details of the chemical composition of their pigments (1892). Only their processess, which had sometimes taken years to perfect, remained undisclosed. Winsor & Newton also published at the same time a statement of policy. No doubt with Turner in mind, they insisted that artists must be allowed to make up their own minds whether or not they wanted to use impermanent pigments. Winsor & Newton would certainly produce them if artists wanted them, but they would not try to enforce "moral laws" on their customers. In any case, they did attempt to make the colours as durable as possible. As to the composition of pigments, they had published several editions of Field's Chromatography, the standard authority on such matters. Moreover, they said, it is part of the training of every art student to attend lectures on Chemistry, as at the Royal Academy. |
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The two thousand gallon vats in which dye is mixed with a substrate in the process of lake making which is one of the oldest traditional processes in the preparation of pigments, and consists in precipitating the liquid dye upon a base such as alumina. This takes place in enormous vats, and the resulting precipitate is passed through a hydrolic filter press to extract the liquid.
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Some colours such as rose madder have been drained through linen filters instead of presses, and this is slower and more expensive. Blocks of colour are left which are placed in trays and dried in large ovens. They are then crushed to a fine powder.
Extracts from PAVEY, D. (1984) The Artists', Colourmen's Story. Harrow: Reckitt & Colman. |
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