A lot is expected of artists’ paints: permanence, ease of use, reliability of tone, and capability of modification with both thinners and thickening agents to suit the techniques of individual artists.
Not many young artists think that paint could lose colour – until they grow older and see that it can. Collectors who love watercolours, and museums and galleries, have always known this. Museums today all reduce their lighting, and make sure they block out ultraviolet light, for watercolour displays. Historically, collectors took watercolours and etchings out of portfolios to admire them but did not frame them. One reason was that many of the traditional watercolour pigments of the eighteenth century lose colour readily: the brighter colours were made by extracting colour from the roots, berries and flowers of plants that themselves only lasted for a season. Blue indigo was mixed with red to give slate-coloured storm clouds, and with plant-based yellows like gamboge and lakes to make greens for foliage – these can shift in tone dramatically as they fade. Only the ochres, siennas and umbers used to paint landscapes in watercolour were resistant to fading.
Even at the middle of the nineteenth century, many young artists including the avant garde Pre-Raphaelite Brothers (their circle included George Price Boyce), would continue to use the some of the traditional colours such as indigo. Telling each other that they were sufficiently resistant to fading for their purpose, they would ask each other whether the newer products supplied by Winsor & Newton were any more permanent. This group of artists did not always ask the company, which could have provided valuable pointers and comparisons of different pigments, especially regarding red lakes, but instead relied on anecdotal evidence from their equally inexperienced friends.
Mr Winsor in fact warned J.M.W Turner about indigo fading in daylight, before 1850. Turner said that was his business, not Mr Winsor’s. When the Pre-Raphaelite Brothers, once so anti-establishment, grew into senior figures who commanded respect, Holman Hunt would care deeply about the permanence of artists’ colours. Holman Hunt and John Everett Millais, founders of the group with Rossetti, are known to have used Winsor & Newton watercolours, as well as other suppliers, this being a period when each company produced unique shades or well-known pigments. Rossetti used watercolour paints from Winsor & Newton for large and complicated works that looked more like oil paintings, and were treated the same way, constantly on view: his red paint used in the 1860s was noted to turn brown. He used red lead, a very traditional material, which was the problem pigment: the severe sulphur-based urban pollution levels at mid-century due to horse-drawn transport and sewage disposal into the River Thames were more likely responsible than over-exposure to light.
The critic and writer John Ruskin, and designers and social reformers like William Morris, promoted public access to art in the later 19th century, including watercolours. The opening hours for viewing public collections now included the evenings, so that workers could visit. Gas lighting made extended opening in winter possible too. This all led to noticeable colour change in some watercolours. Soon research was commissioned and, in 1888, the Russell and Abney report on the action of light on watercolours was presented to both houses of parliament. The colour range they investigated (’from one firm’ they stated) and the red lake colours in particular, suggests Winsor & Newton paints. The report was very thorough and very easy to understand. But in Britain, it would be well into the 20th century before every supplier of artists’ paints, including Winsor & Newton, would mark all their ranges and all colours with a permanence rating, as is done today.