The rise and fall of cadmium salts as pigments is a strange story, driven by misunderstandings and market forces.

Cadmium itself wasn’t discovered until recently – 1817 – and then only by a chance observation of abnormal yellow colouration of a sample of what should have been zinc carbonate. The brilliant yellow colour of its salt cadmium sulphide was noticed the following year, but it wasn’t exploited as a pigment until the 1840s, when it became possible to manufacture it in quantity.

Nevertheless, it has been claimed that it was used as a pigment for oil paints as early as 1829, and by 1851 it was shown by Winsor & Newton at the Great Exhibition at Crystal Palace in London. But it remained extremely costly.

Few artists could afford to use Cadmium Yellow until its price fell late in the nineteenth century. Claude Monet was among its early users, in this painting of The Artist’s House at Argenteuil from 1873. Before this, William Holman Hunt and others had reported that its colour was “capricious”, sometimes fading rapidly to “the colour of dirty beeswax”. With the alternative of Chrome Yellow more readily available and much cheaper, most artists steered well clear of the new pigment.

Monet’s love of the pigment continued to grow, and he used it again in Still Life with Apples and Grapes in 1880. He appears to have been fortunate in securing a supply of high quality which has proved thoroughly stable.

Bordighera from 1884 is perhaps the most famous of Monet’s works to use Cadmium Yellow, which attests not only to his sustained use of the pigment, but to his commercial success which enabled him to afford such expensive paint. Even by this time, few other Impressionists could have justified the cost.

Monet must have been very grateful to have been using it when painting dawn or dusk, as in his Stacks of Wheat (Sunset, Snow Effect) from his 1890-91 grainstack series.

It is commonly, and quite incorrectly, claimed that Vincent van Gogh used Cadmium Yellow for his famous paintings of sunflowers, including Still Life, Vase with Fifteen Sunflowers from 1888. Analysis has shown that those rely instead on the better-established, and then much cheaper, Chrome Yellow.

However, van Gogh did use Cadmium Yellow in his still life of Grapes, Lemons, Pears, and Apples in 1887. Whether he was deterred by its high cost or simply preferred Chrome Yellow, I don’t know.

For those who could afford it, Cadmium Yellow also worked excellently in watercolour. Winslow Homer came to use it later in his career, for example in his Hunter in the Adirondacks of 1892.

It appears in several of John Singer Sargent’s later watercolours, including Olive Trees, Corfu from 1909.

It has been found, perhaps mixed in some of the greens, in Sargent’s watercolour An Artist at His Easel from 1914.

Léon Bakst used Cadmium Yellow in his watercolour paintings of costume designs, here for the character Pretres Agni in The Blue God of 1911.

Bakst’s design for a young woman in a red bonnet, for Ballet Boutique Fantasque in 1917, is one of relatively few paintings which have been found to contain Cadmium Orange, obtained by adding small amounts of the more novel selenium to cadmium sulphide.

In the early twenty-first century, many ranges of artists’ paints offered several cadmium-based colours ranging from lemon to full red.

By the end of the First World War, cadmium production had increased greatly, and the cost of Cadmium Yellow had fallen as a result. Another development which helped popularise the colours was the manufacture of lithopones by admixing barium sulphate, during the 1920s. These were half the cost of pure Cadmium Yellow, yet proved almost as lightfast and stable.

Charles Demuth used Cadmium Yellow in at least two of his exquisite floral watercolours, including Fruit and Sunflowers from about 1924-25. He painted these as therapy when recovering from episodic complications of diabetes.

In the twentieth century, cadmium pigments became widely used to make brightly-coloured plastics, particularly those for domestic use, and the consumption of pigment for artists’ paints was relatively tiny. It was then that cadmium fell from favour.

Cadmium salts are notoriously toxic, something discovered soon after their introduction. However, when locked into pigment particles, their insolubility makes them of very low risk, unless they are dispersed in dust which is inhaled, as could be the case when incorporated into soft pastels. This lack of immediate threat lulled users into a false sense of security: it turned out that cadmium (as with other toxic pigments) posed major environmental risks.

In the twenty-first century, evidence has accumulated that cadmium pigments can become concentrated in sewage sludge, which is often applied to fertilise agricultural land, resulting in increased dietary intake of cadmium, which is in turn associated with long-term medical problems such as osteoporosis and bone fracture, and some cancers.

None of this should have been any worry for artists, whose use of cadmium salts is tiny relative to industrial uses, including most notably rechargeable batteries. Except that most artists had almost no awareness of their impact on the environment, and have been happily discharging pigment-rich waste into the sewage system.

Instead of educating artists to minimise their impact on the environment – which applies equally to other pigments – environmental organisations instead proposed a ban on the use of cadmium pigments in artists’ paints. This in turn scared artists and their paint suppliers into a self-imposed ban, in which many paint ranges no longer include cadmium pigments, and art schools won’t use them because they’re “toxic”.

When all that was required was a little care in processing waste water rich in pigment, for example – actions which are still required to handle other pigment hazards which haven’t (yet) become scary. Humans are sometimes so irrational.

Reference

Inge Fiedler and Michael Bayard (1986) Artists’ Pigments, vol 1, ed Robert L Feller, Archetype. ISBN 978 1 904982 74 6.