The History of Pigments
"Today's artists work with colours produced by an industry which has spent two centuries getting better and better and better,whilst most people in this world have to work with things that have got worse and worse." Emma Pearce quoted in Paints and Colours by David Pyle, Krause Publications 2000.
We are certainly lucky in being constantly provided with pigments of better permanence and an ever widening choice of handling properties. In less than 200 years the finest quality ranges have gone from around 30% permanent to 99 - 100 %, as well as providing two or three times the number of colours to choose from.
Although many early pigments have been replaced by more reliable ones, many have not, and the incurable romantics amongst us find it pleasing to know that the very first pigments remain some of the very finest available to the artist.
The first colours
More than 15,000 years ago cavemen began to use colour to decorate cave walls. These were earth pigments, yellow earth (Ochre), red earth (Ochre) and white chalk. In addition they used carbon (Lamp) black by collecting the soot from burning animal fats. These colours were all that were needed to produce the sensitive and exquisite drawings and stencils which we are still able to see today.
By 4,000 BC the Egyptians show evidence of serious colour manufacture. The earths colours had been cleaned by washing, increasing their strength and purity and new pigments appear from the use of minerals. Perhaps the most famous is Egyptian Blue, first produced around 3,000 BC. This was a blue glass made from sand and copper which was then ground into a powder. It was replaced in the 16th century by Smalt which was itself finally superceded by Cobalt in the early 19th century.
The Egyptians also utilised Malachite, Azurite and Cinnabar by crushing and washing each mineral. Cinnabar was prized as the first known bright red.
Vegetable dyes were also developed by the Egyptians, who found a way of ‘fixing' the dye onto a transparent white powder to produce a pigment. This process is called lake making and is still used today to produce Rose Madder Genuine.
Although the discoveries and inventions of the Chinese civilisation ran in parallel with other ancient socieities like the Egyptians, the Chinese were the first to invent many things like clocks and paper well in advance of the rest of the world. Pigments were no exception and Vermilion was developed in China around 2,000 years before it was utilised by the Romans. Vermilion was made by heating mercury and sulphur, producing an extremely opaque, strong red pigment which had almost entirely replaced Cinnabar by the 18th century. By the end of the 20th century, Vermilion was replaced by Cadmiums which provide greater permanence.
The Greeks and Romans
The Greeks also added to the artists' palette, namely by manufacturing white lead, the first fully opaque white (Flake White, Cremnitz White). This took several months, by stacking lead strips in a confined space amongst vinegar and animal dung. This method (with a few refinements!) was used until the 1960's and produced arguably the finest pigment of all for the artists' palette. The physical structure and reaction with oil give a superbly flexible and permanent paint film. The Greeks also made red lead, which was used for priming metal until the 1990's when lead pigments were banned for use by the general public.
For the most part the Romans inherited the palette of the Egyptians and Greeks. Pompeii is one of the main historical sources, dating to AD79. Vermilion has been identified on the wall paintings numerous times. One of the most important colours was Tyrian Purple, also being one of the most costly. The colour is prepared from a small colour producing cyst within a whelk. Huge quantities of whelks were required and spoil heaps of the shells can still be seen on the sites of ancient dye works around the Mediterranean. In 1908, P. Friedlander collected just 1.4 grams of pure dye from 12,000 mollusks. Due to its price, Tyrian Purple was used to dye the togas of Roman Emperors.
Little changed in the first millenium AD for artists and it was the rebirth of artistry which fuelled new pigment development from the 14th century.
The Italians further developed the range of earth pigments by roasting siennas and umbers to make the deep rich red of Burnt Sienna and the rich brown of Burnt Umber. Earth colours featured heavily in their painting technique, Terre Verte (Green Earth) being the principle underpainting colour for flesh tones.
The Italians improved the lake making processes of the Egyptians and developed Naples Yellow, another opaque lead based pigment, but it was the development and use of Genuine Ultramarine which perhaps personifies Renaissance paintings in our minds.
Lapis Lazuli was first used as a pigment by simply grinding it, but even the best stone can have up to 90% impurities and it was the discovery of how to extract the blue which enlightened the Renaissance palette. The bright, deep blue produced had excellent lightfastness and was the most expensive pigment known to man. This high value was the reasoning behind the Madonna being graced in blue.
The beginning of modern pigments
By the 18th century the world was not only enjoying greater trade between continents and therefore more industry than previous centuries but also beginning to see the benefits of modern scientific chemistry.
In 1704, a German colour maker named Diesbach was manufacturing red lake pigments, which required the use of potash as an alkali. He ran out of his supply and used some which was contaminated with animal oil. Instead of getting red he got purple and then blue, the first chemically synthesized colour, Prussian Blue, had been made! Prussian Blue remains a popular colour to this day and is also known for its novel ability to fade in daylight yet recover in darkness!
The early19th century
The Industrial Revolution at the beginning of the century produced both new processing possibilities and new opportunities for trade in every quarter of life including artists' pigments. Scientists were driven by the demand for new more permanent colours and were able to utilise new minerals and chemistry to invent many of the colours which we think of today as ‘traditional'.
Cobalt Blue was discovered in 1802 by Thenard, a wonderful transparent, granulating blue of great permanence. It is used widely in ceramics and loved by artists for its moderate tinting strength, fast drying and water colour characteristics. Cobalt Green though first made in 1780 did not enter common usage until after Cobalt Blue. Cobalt Violet first appears in 1860 with Cobalt Yellow (Aureolin) becoming available in 1862. Cerulean Blue is also a type of cobalt and was available as early as 1805. By combining cobalt oxide with aluminum, phosphorus, tin, zinc or a number of other metals, the variety of colours are produced. The cobalt pigments have always been expensive and the search remained for a lower cost dark blue pigment for the artists' palette. In the 1820's a national prize of 6,000 francs was offered in France to anyone who could discover a method of artificially making ultramarine at a cost of less than 300 francs per kilo. Both the French and Germans competed but it was J B Guimet who succeeded in 1828. Known as French Ultramarine ever since, the pigment is chemically identical to genuine ultramarine but physically finer and is without the impurities of the lapis rock.
The isolation of new elements in the late 18th century also played a part in providing new colours. Deposits of chrome in the USA in 1820 facilitated the easy manufacture of Chrome Yellow, a highly opaque low cost colour available in a variety of hues. Although Chromes had a tendency to darken they remained popular until the 1990's due to their good covering power and economical price. Chemically the colours are lead chromes and as such they fell foul of the legislation against lead pigments at that time.
Similarly, the isolation of Zinc in 1721 eventually gave rise to Zinc Oxide by the end of the 18th century. This was utilised as an artists' white in preference to lead white as it was less hazardous and more permanent particularly in water colour. However it lacked opacity until 1834 when Winsor & Newton developed a method of heating the oxide to increase its opacity. This new type of Zinc Oxide was called Chinese White.
In 1817, the metal Cadmium was discovered by Stromeyer but it was not until 1846 that Cadmium Yellows were introduced to the artists' palette. Immediately popular for their great permanence, range of hues, moderate tinting strength and high opacity, Cadmium Yellows remain the mainstay for artists in this area of the spectrum. Cadmium Red was not available until after 1910.
And finally, this part of pigment history could not be complete without mentioning two famous colours in the artists' palette. The first, Indian Yellow was a beautiful, transparent colour with excellent lightfastness. It was however produced by feeding cows exclusively on mango leaves and using the resultant urine to manufacture the colour. Using the cows in this way was unacceptable in India and by the early 20th century the practice had ceased. Indian Yellow has since then been made with a variety of pigments but it took until the 1990's to find pigments which provided the lightfastness of the original.
Genuine Emerald Green was first documented in 1822 and was highly toxic. Consisting of copper aceto-arsenite it provided a bright clean emerald colour until the 1960's. It is most famous however for its potentially fatal effects. It is thought that Napoleon died as a result of arsenic poisoning from the wallpaper in his prison home on St Helens. Emerald Green was a very popular wallpaper colour but unfortunately in damp conditions arsenical fumes were released. Shortly before the colour ceased to be available it was quoted as the cause of death of a Broadmoor inmate who had secretly collected enough by pretending to paint in order to commit suicide!
Pigments - Modern
The first beginning of modern pigments
In 1856, William Henry Perkin was a student at the Royal College of Chemistry. In his improvised laboratory at Greenford, Middlesex he was attempting to synthesize quinine when he unexpectedly produced a purplish dye from oxidising impure aniline with potassium bichromate, Mauvine, the first organic (based on carbon chemistry) colour was born. This led to the distillation of coal tar which produced a huge range of new pigments over the decades to come.
Mauvine as a dye was an instant success and became the very most fashionable dress colour for Victorian ladies.
Alizarin Crimson is arguably the most important organic pigment of the 19th century. It was introduced in Germany in 1868, providing a blue shade crimson of strong tinting strength and high transparency. It was immediately to become a core colour in the common palette. At the time and until the 1960's it was the most permanent crimson available, however in pale washes it is susceptible to fading and modern quinacridones are more lightfast.
Synthetic iron oxides
The 19th century also saw the development of the Mars colours. These ‘earth' colours are produced in a wide range of browns, reds, yellows and black according to the levels of moisture and heat used. Originally they tended to be opaque and are very much stronger than the natural earths. They have become important in the 20/21st century as the deposits of good natural earths have been depleted.
The explosion of new pigments during the 19th century, the invention of the metal tube and the arrival of the railways all combined to facilitate this movement in painting. Bright new colours in portable, stable tubes and a method of easy travelling around the country provided us with paintings from one of the most famous periods ever.
The 20th century
Pigment development continued apace into the new century.
During the first decade the Hoechst company brought out the first ‘Hansa' yellows. Here was a synthetic organic pigment of good permanence, clear bright hue and high transparency. We know it as Lemon Yellow but the group quickly gave rise to darker yellows and this pigment type is still important today. The chemistry of this and other synthetic organic pigments is immensely complex. In words, they are made by coupling diazotised amines containing nitroso and/or halide groups with acetoacetanilide or one of its derivatives! No longer can they be called a basic name relating to their origin, like cadmium or cobalt. Instead we see trade names, like ‘Winsor' Yellow or sometimes shortened names like Azo Yellow Medium. Reds were similarly developed and from the 1920's onwards these new pigments began to appear in artists' materials.
The most important pigment in volume terms of the century was Titanium White. Although the element had been identified in 1795 it was not until 1920 that an economical method of purifying the metal oxide was established. The non hazardous, strongest, most opaque white; Titanium quickly became the most popular white amongst artists.
In 1936 Monstral Blue was introduced by ICI. Known to us as Phthalocyanine or Winsor Blue, this offered a deep transparent blue of enormous tinting strength yet moderate cost. Prized for its mixing abilities it has also become the basis of many student range blues as it can be reduced and still offer a strong colour.
A very important group of pigments originated in the 1950's. The first quinacridones were introduced to the artist's palette as Permanent Rose and Permanent Magenta. The pink and mauve colour area up till then had suffered from poor lightfastness, now crystal clear hues were available without fading! Over the next 50 years many more colours became available from deep crimson to gold. This is achieved by juggling the chemicals involved. It is a quinacridone which is used as Permanent Alizarin Crimson.
Can it get any better?
By the 1990's more pigment types of synthetic organic origin were appearing. Perylenes, Pyrrols and new arylides (eg.Hansa yellow) have come into use. In some cases new hues are available, further extending the possibilities in water colour or filling a perfect gap in portraiture or even greater transparency for mixing or glazing. In other cases some good lightfast pigments are replaced by even more lightfast pigments, we go from no change for hundreds of years to no change in hundreds and hundreds of years! We are most certainly fortunate to be living and painting now, many a past painter must have twitching fingers wishing to be alive now!
Thanks to the automobile!
The car, has to endure permanent outdoor weather and sunshine in snowbound or desert conditions. That's a tall call for a pigment. Artists have everything to be thankful for that such lightfast pigments had to be developed, without the car we wouldn't have the reds, yellows and purples which we enjoy today.
Artists' pigments today
An average palette today of only twelve colours contains a selection of pigments from every historical era as well as every pigment type. Broadly defined we recognise three pigments types;
i) Earth colours - ochres, siennas, umbers, Mars colours
ii) Traditional colours - cobalts, cadmiums, titanium, ultramarines
iii) Modern colours - phthalocyanines, quinacridones, perylenes, pyrrols
Chemically, pigments are categorized by whether they contain carbon or not; this results in a more technical but more accurate definition of possible types. Recognisable examples are given in italics;
i) Inorganic - earth, mineral (cinnabar), synthetic (cobalt)
- ii) Natural organic (Rose Madder)
- iii) Synthetic organic (quinacridone)
Like all things we try to make sense of them and gain trust by setting universal standards. There are a number of systems which help artists to identify and build knowledge in key areas of concern. Most importantly we are interested in the characteristics of pigments, we as artists want to use them to our own creative ends. Secondly we want permanence information. The characteristics of a colour are to be found in both reference books and manufacturers' colour charts, granulation, staining, bleeding, transparency/opacity, colour bias, drying rate etc. Permanence ratings are also provided by manufacturers.
Per se, there are no set standards at this level, after all it is the diversity and individuality of each material which painters want to exploit. We are lucky in having a very high class of product from the whole industry and for most of us the information supplied is sufficient for our needs. However, you may want to know more and to do this pigments need to be identified.
Since the development of modern organic pigments, pigment names are no longer sufficient to identify the actual pigment being used, there are dozens of Naphthol reds with varying characteristics and different levels of lightfastness. The Colour Index International identifies each pigment (see page..) ensuring we know what we are using, most artists' materials manufacturers publish the pigment content of their colours.
The ASTM abbreviation stands for the American Society for Testing and Materials. (The UK equivalent is the British Standards Institute). ASTM has set standards for the performance of art materials and this includes lightfastness. It is the lightfastness ratings which artists are most familiar with. Pigments are tested in reduction with white in both artificially accelerated conditions and desert sunshine. Ratings I and II are recommended as ‘Permanent for artists' use'. Art materials manufacturers rate their colours in a similar way and where no ASTM rating is given this usually means the pigment is new and has not yet been tested by ASTM. In these cases the manufacturer's rating will be available.