Moving Movements, History of Modern Painting, history of colours

Modern painting was the child of industrial revolution, and change in social and political situations. But of coarse it was also deeply influenced by the development of paint, such as pigments or the invention of tubes. In this subject we cannot restrict us to the period of 1800 to 1950, because a lot of techniques and pigments used at those times were already going on for a long time, while new ones were invented. For Europe, we even start long before the first humans did arrive! In modern times, an explosion of new colours took place, while certain antique colours maintained. Now other antique colours even have a comeback.

The first painters

It was a striking and recent discover that the first painters in Europe where not humans, they were the Neanderthals. The earth colours were digged in mines, prepared for use and painted by specialists, painters, travelling from cave tot cave, they required great skill and de paintings show similarity. In three different caves, spread over Spain, wall paintings are more then 65000 years old. First humans arrived in Europe, 40- to 45000 years ago. At Cueva de los Aviones perforated seashell beads and pigments where found at least 115000 years old. The same stenciled hands are found in an Indonesian site in 2014, and in caves in Spain, 40000 years old. They are made with an airbrush technique, blown from a pipe. Neanderthals adopted human kids and learned them all their skills. Europeans have about 4 to 8 % DNA of Neanderthals (Africans about 1.3 %).

Outside Europe human painting is found from 250000 years old. Ochres where used in the earliest cultures of India and Australia. It was also roasted to become red ochre. Umber naturally contains iron and manganese oxide. Other colours were used: white from pipe clay, black from manganese and green earth from celadonite.

The pigments used by prehistoric people where the so-called earth colours, the digged minerals limonite, hematite, red and yellow ochres, umbers (all iron oxids), as well as carbon black from the fire, bone black from burned bones and lime white from grounded calcite.

Everywhere prehistoric sites are found, near or more distant where hematite mines. Sometimes cave men travelled 25 miles for the good quality ochres. Their use was not restricted to cave paintings, pottery and tattoos. According to the paleontologist Carlos Duarte using red ochre as a pigment in tattoos or even ingested may have had a role in human evolution, as a source of iron for the human brain, perhaps making us smarter. At a site called in the Kapthurin formation of Kenya, 11 pounds of ochre was discovered in more than 70 pieces.

Used techniques were brushing, smearing, dabbing, and spraying. Beside fingertips, twigs, crayon sticks and feathers, also brushes have been found. Blowing pigments with hollowed bones require fine grinding, to which mortars were used. The pigment was made into a paste with various binders, including water, vegetable juices, urine, animal fat, bone marrow, blood, and albumen.

Riebeckite is a dark blue mineral & has been identified on wall paintings in Late Neolithic and Bronze Age in Europe and the eastern Mediterranean. Before the Greek invented white lead, chalk was used, calcite or calcium carbonate, fossilid remains of plankton algae. In the renaissance this was still in use for gesso. Chalk white becomes transparant when mixed with linseed oil. Since Neolithic time bone white was also used, the first colour made by transformation. Bone black is found in prehistoric, Egyptian, Greek and Roman art.

Egypt

Egypt was the empire of colour above all. Beside the continuation of the use of earth colours, a lot of new and bright colours arose, white, violet, greens, blues and gold. A lot of pigments where digged in mines, some of them already before the dynasties, such as lead pigments, or malachite (perfectly lightfast in tempera, less in oil). ergens moet staan met welk proces de Egypt. op muren schilderden.

In 3400 BC the Egyptians started painting on walls in several colours. In 3000 indigo was certainly used (dye from the leaves of Indigofera tinctoria). Azurite is found in the upper layers of copper ore (erts) deposits, together with malachite. Lazurite was imported from Afghanic mines, already exploted 6000 years ago (foto graf Toetanchamon).

Egyptians painted their colours pure, juxtaposed, with strict rules of use. Mixing was only allowed to enhance a certain colour, such as malachite and antacamite (hydrated chloride of copper) for green. Yellows where sometimes painted in three superimposed layers, first yellow ochre, then orpiment (arsenic trisulfide- from the Latin auripigmentum, gold pigment), on top jarosites, minerals with sulfates of iron, potassium & sodium. Realgar, a natural mineral of arsenic sulfide, from the same deposits as orpiment but less permanent, is an historical pigment having been found as early as the fourteenth century B.C. as lumps of raw pigment in an Egyptian tomb. It was a painter's favourite from Mesopotamia to India and the Far East.

The Egyptians where also making quite some pigments artificially. Lead antimonate yellow (now called genuine Naples Yellow) was manufactured as early as the 18th Dynasty (16th-14th century B.C.) at Thebes. Ceruse, basic lead carbonate, was a mineral, called cerussite. It has not been used a lot, soon replaced by artificially made lead white (corroded lead). This has an extreme high lightfastness in oil and encaustic, but less in watercolour & true freso, since it can blacken as a result of sulphur air pollution (as from later coal burning and gass lights).

The first synthetic pigment, not found in nature, was Alexandrian blue, now often called Egyptian blue made from about 3000 years BC, by combining quartz, chalk (calcium carbonate), malachite (copper carbonate) and soda ash (sodium carbonate) and heated from 900° to 1000° C. Later on it was exported in great number to Romans and Greeks. Pliny described it under the name caeruleum blue, meaning colour of heaven. After the fall of the Roman empire it got forgotten.

The Egyptians also manufactered a darker synthetic blue, greenly tinted, with cobalt, ancestor to Delft's blue. In the grave Toutanchamon were found: Egyptian blue, metallic reds found in silver and gold mines, yellow made from arsenic, bright green made with copper suspended above sour wine and white from corroded lead. The Egyptians imported kermes from Mesopotamia. Kermes vermilio is a wingless scale insect that lived on the kermes oak tree in Southern and Eastern Europe, a red dye harvested by scraping it form the branches, and cooking in lye. The blue chrysocolla (meaning 'golden glue'), a hydrated copper silicate, found in the same ores as malachite and azurite, but slightly greener and paler than azurite.

Romans

Of the Greek fresco's few survived, but he rediscovered cities of Pompeii show us remerkable wall fresco's (1th century AD). In fresco the paint is embedded in the wet plaster, leaving no means to correct, nor the use of certain pigments, as lead white, realgar, orpiment & indigo. Red & yellow ochres (also heated) where used, whites composed of calcium, carbonates (calcite or aragonite), clay and carbon blacks. Plus Egyptian blue & cinnabar as the most costly (digged vermilion).

Egyptian blue, green earths (clay), cinnabar (mineral vermilion), arragonite white & yellow ochres, where used in Brittany, Gaul, Romania, Scandinavia, the Near East & North Africa. A coffer of a Gallo-Roman oculist, 2th century AD, contained as minerals white clays, hematite, goethite, azurite, malachite, white lead & realgar. Without the inscriptions as eye medicines, they could be taken for an artist's paintbox.

Verdigris was a blueish green, made of corrotion of copper sheets above vinaigre. It is not highly colourfast, reacting on sulphur containing pigments, such as lazurite or orpiment. The Greek called it copper flowers, the Romans aeruca.

Violets where made of murex, a mollusk secretion (from the Bolinus Brandaris), found in Tyran (Phoenician, now Lebanon), but more often from violet hematite, heated hematite, or by mixing Egyptian blue with red ocher. Minium (red lead, an oxidation product of lead) have been made artificially since antiquity.

Cretan and Greek painters had created green tones by layering yellow & blue, but Romans made green-earth pigments with rocks rich in green clay (glauconite, celadonite, chlorite). Glauconite was spread from Mesopotamia to Norway. Also artists made lakes, vegetale and animal-based dyes with white mineral powder as pigment base (clay, aluminium or calcite). Caledonite, a more bluish green, higher valuated by artists, was costly and rare, such as baldogean, or Veronese earth, digged on Cyprus. Caledonite, glauconite & Egyptian blue where also mixed. The wreckage of a ship from 47 BC revealed Egyptian blue, litharge yellow (lead oxide) & realgar.

Roman dyers used madder, weld (yellow) and indigo, with the right mordant to woll, coton or linen. Tyrian purple, used since 3500 years, was very costly, it took to 10000 mollusks for a gram of the dye. Sometimes two baths where given, becaus the Northern murex was different from that of the South. The second could be replaced by kermes (carmine-karmijn) or indigo.

The same pigments from wall painting and sculpture painting were also used for medicins and cosmetics. Kohl for the eye for example contains galena (black sulfide of lead), ceruse (basic white lead carbonate) & chlorides of artifial lead, to prevent eye infections. For textiles a lot of dyes where also used, they where not meant to last for centuries to come, madder plant for red, & safflower. According to Plinius, also indigo, kermes, archil (a lichen), arkanet (roots), buckthorn berries, mulberry juice & tannins. Lead white was made in ancient Greece with lead above vinagre in earden pots, kept in horse dung. Originally it was taken from the mineral cerussite. It was also added in food as a sweetener by the Romans.

The Maya's blue

Maya blue was made by the Maya's from dark blue dye, just as indigo is. Dyes are from plants and living colours never lasted long, so mirerals (anorganic) where preferred as important paints. But Maya blue has faded little in over 6000 years, probably because of it's mixture with the palyorskite clay. It is an old paint (still made by Rublev). It has long been a secret how they managed to make also a very permanent water based paint with it. Quite recently the answer has been found and horrifies us. The Maya's brought a lot of human offers to the gods in time of dryness. It was known their heart was cutted out en raised up to the gods, while the victim was still alife, the heart still had to beat on that time. Now this victims where skinned alife before the ceremony and painted completely with the oil Maya blue. After the ritual the body's where thrown in a giant well. The blue pigment sank slowly to the bottom of the well. That sediment was used to make the fresco pigment Maya blue.

Middle ages

With the fall of the Roman empire a lot of knowledge of the antiques vanished, but some pigments where still found in Carolingian & Romanesque fresco's, as ochers, green earths and Egyptian blue. Very bright colours revived in the Middle Ages, such as vivianite, royal smalt, and from years 1600 barite white. The great international textile industry of Medieval Europe was largely responsable for the quest for new colours. There was a big difference between dyes for common people or for the rich. In painting lazurite replaced Egyptian blue, folium violet and rose-madder replaced the animal purple, not to find anymore. Malachite and chrisocolla were replaced by verdigris, orpiment by lead-tin yellow. Parchment and paper replaced papyrus, while linen canvas was painted on an easel.

Medieval painters mostly used mineral pigments. Most important where lazurite (lapis lazuli) and azurite for blue. Copper resinate and earth greens were mixed with blue, for yellow orpiment (arsenicum) was used. Minium and vermilion were reds. Red and black ochers were used, and lead white (ceruse). Malachite was called verde azzurro. Also lakes where used, the tinctorial extract were affixed to mineral substances, to make the colors insoluble. Kermes lake was made from cochineal, brazil red, Persian berries for a yellow lake, indigo blues and variuous red and rose madders. Dark red was made from hematite. A red violet called folium made from French tornsole, replaced the rare Tyrian purple. White earth from Selinus (Sicily) and chalk from Eretria where often replaced by eggshells or calcinated bird bones. Gold was used in different ways, as ink, in thin leafs, or an amalgam used in gilding. A bronze colour was obtained by powdering brass. Pigments where mixed with white and glazes where used as top layer.

Some mixtures where permitted, others not. Orpiment was not to be mixed with any other colour because it tend to bleach on the page and affect other colours. Vermilion could be mixed with madder lake or dragon's blood (warm ruby-red resinous exudation of Calamus Draco). Vermillion was covered with madder lake and gum arabic to prevent bleeding. To prevent interaction, colours could be seperated by certain other colours, or painted in dried layers.

Alchemists, working a lot with metals, devellopped new synthetic pigments. They made vermilion and sulphur from sulfer and mercury, orpiment yellow (as a mineral orpiment was rare) with sulpher and arsenic, and a gold yellow, called mosaic gold, by marrying sulfur, tin and mercury.

Lead-tinoxyde came up in Flanders in the 14th century, called masticote, replacing light unfast lakes or the unmixable and very toxic orpiment. It was also mixed with lazurite to make green.

In the 15th century painters began to place contrasting colours together to create optical vibrations. Cross-hatching in gold and violet lines made reds and greens vibrate. For metallic sheens, such as in armors, grisaille was made with colloidal silver.

In flames red lake of brazilwood was laid over vermilion to create a bright effect, columbine lake over lazurite for a red violet.

In the 15th century, cochineal was a stronger red, discovered in America, where it was already used as a dye. From the 15th century smalt was used as a blue, a cobalt glass, it was used grinded to replace lazurite and azurite. It had to be painted in several layers. The yellowing of the oil reduced the blue to grey. From the 15th century, blue verditer, a basic copper carbonate, was most used in painting, because it was a lot cheaper then azurite or lazurite. It had a tendency to turn green.

In the15th century Jan Van Eyck was brought up in the techniques of tempera and stained glass. In stained glass, more layers of glass are used. To make a violet, a red glass was placed over a blue in the same settings, sometimes with a thirth white glass between them to augment the brilliance. Van Eyck used oil and with this medium he could paint in transparant layers, as with glass. In the same painting he also continued to use tempera painting technique, as for painting flesh, jewels and draperies.

16th to 18th century

In the 16th century, beside mural painting, wood panels, polychrome sculpture, enamelware and ceramic objects, painting also was done on linen stretched over a wooden frame, with a first layer called imprimatura. New oil binders, egg tempera and varnishes where used to accentuate light and shadow, for effect of depth. With new materials, the permanance of colours required care. Best were lead white, vermillion, earth colours, tin yellows and copper greens. Lead white was now be made by the stack method, with lead and vinaigre in ceramic pots. Cornelius Drebbel popularized the use of tin chloride as a mordant for scarlet dyes, becoming carmine similar to kermes. Cocchinal was bought in Indochine and Burma and very expensive.

Lead-tin yellow has been found frequently in oil paintings before the 18th century, mixed with lead white, vermilion, yellow lakes, ochres, verdigris, indigo and azurite. Lead-tin orange is an artificial pigment made by heating lead and tin oxide together and is a reddish hue of lead-tin yellow (type I), which frequently occurs in European painting before the 18th century. Orange Molybdate is found in paintings before the 18th century. Raphael, Leonardo da Vinci and Michelangelo Buonarotti used the pigment lazurite.

In old European paintings, vermilion was overpainted with red glazes of madder, kermes and cochineal lakes, which makes it lasting for ages. Red mercuric sulfide is prepared according to a Chinese ancient process.

Lead antimonate yellow (Naples yellow) gained its highest popularity in European art between 1750 and 1850 after which it was replaced by lead chromate yellow and finally by cadmium sulfide yellow. Since the fifteenth century B.C. it was the only yellow colorant in general use, then it was gradually replaced by lead-tin yellow.

Orpiment was now available manufactured. Diesbach and Dieppel accidentely discovered Prussian blue, a dark blue from cyanide, potassium and iron, around 1704. By working with cochineal red, Diesbach felled out of alcali and asked Dieppel for some potash. But it was contaminated with animal blood. In trying to concentrate it, the blood started a chemical reaction, leading tot the dark blue ferrocyanide. Available from 1724 it replaced the expensive lazurite. Manifacturing started in 1710, with some variants as Parisian blue and Antwerp blue. Scheele, 1742-1786, discovered a green with oxygen and copper arsenite, called Scheele's green. Vauquelin dicsovered chromium, Roman alum was replaced by synthetic alum.

Regarding theories about color, Chevreul created the first chromatic wheels and established the law of contrasting and complementary colours. Verdigris remained the most vibrant green untill the 19th century. It was not to be mixed with lazurite or orpiment, because sulphur let it be blackened. Often layers were separated by varnish, nevertheless in a lot of renaissance paintings this green is now very dull. Giallolino (yellow=giallo) is lead tin yellow, also to keep seperated from sulphures pigments. In the north of Europe is was called massicot. Gamboge was a rubber extraction taken from the Garcinia tree, Cambodia ever was the principal country for supply. In the 8th century it was already used in inks in China, Japan and Thailand. In the beginning of the 17th century it was supported to Europe for a warm, transparant yellow. Flemish painters used it with oil, but it as as it's best in watercolours. It was preferred by JMW Turner. It was also mixed with Prussian blue or indigo to make Hooker's green. Organic, it was not that lightfast. Mummie brown or mummia, caput mortuum (dead head) started being used, it became popular in the 18th and 19th century. It was made from the flesh, bones and wrapping of mummified Egyptian humans or animals, as a transparant rich brown for glazing and shading in oils.

Palettes during renaissance and baroque were still limited, restricted to the most reliable and with most mixing possibilities. Let's have a look at some. The palette of Peter Paul Rubens according to Birren: leadwhite, yellow ocher, yellow lake and orpiment, red ocher, madder and vermilion, lazurite and azure d'Allemagne (cobalt blue), vert azur (cobalt oxide), terre verte (green earth), malachite green, burnt sienna and ivory black (or charcoal, black earth). However the cobalt could have not been used, instead azurite or smalt for blue, malachite or verdigris for green. Rubens did make a violet from white lead, charcoal and madder lake or cochineal lake.

Palette of Titian (Tiziano Vecellio): lead white, lazurite, red ocher, red madder, yellow ocher, orpiment, burnt sienna, bone black, malachite. But Titian also used realgar, while most other painters replaced it by minium.

Palette of Rembrandt van Rijn: Azurite, Smalt, Lead-tin yellow, Yellow ocher, Red ocher, Vermilion, Madder lake, Carmine lake, Raw Sienna, Burnt Sienna, Raw umber, Burnt umber, Cassel earth, Brown ocher, Lead white, Bone black.

Palette of Vermeer van Delft: Azurite, Carmine, Charcoal black, Green earth, Indigo, Ivory black (bone black), Lead white, Lead-tin yellow, Madder lake, lazurite, Red ochre, Smalt, Weld, Verdigris, Vermillion, raw umber, Yellow ocher, vivianite & schijtgeel (a lake).

In the 17th century the Italians perfected the manifacture of lead antimoniate, Naples yellow, no longer needed to digg it up at the Vesuvius mountain, patented in England from 1780 as 'patent yellow'. In 1765, Siberian red lead was discovered in the Ural mountains, called crocoite, providing an orange colour. In 1797 Vauquelin, analizing a sample, discovered the metal chronium (from chrome, Greek for color). He made pigments with it, the best was a brilliant and opaque yellow, a lead chromate, easy to manufacture. With chromium he also invented viridian green. In 1804 a chromated iron was found in France. Kurtz, a disciple from Vauquelin, manufactured chromium-based pigments from 1816. From 1862 English greens where made from Prussian blue and chronium yellow in Manchester.

In the latter 18th and first half of the 19th century, other colours where made or perfected. Among them Burgundy violet, two types of ultramarine, cobalt blues, chromium green and reds, copper and arsenic greens, Mars yellow, orange (synthetic oxides), zinc white and a number of lead whites, such as Kremnitz white. Firms came up for producing artist's colours, such as Sennelier or Lefranc&Bourgeois. Indigo was more a textile dye, now produced in the Carraiben and later by the English in India. In 1880 synthetic indigo was made, replacing the Indigofera tinctoria, already cultivated for dye in the Indus valley 5000 years ago.

Palettes became more complex in the time of clasicism and romantism, often with a basic palette and occasional use of a lot of other colours.

In 1766 William Reeves began selling the first water soluble dry cake watercolors. By 1780 a bit of honey (a natural humectant, attracting and retaining moisture) was added to the formulation to make the paint pliable for manufacture in various ways. By the mid to late 1830s inexpensive painting sets with little porcelain pans of moist watercolors were introduced to the general public to compete with the harder pressed cakes. Winsor Newton introduced their glycerine-softened formula moist cakes in 1835.

19th century

In 1798, Napoleon's Egyptian expedition rediscovered Egyptian blue, in the 1880's the chemical composition was identified and the colour recreated.

In 1883 the origin of Indian yellow came clear and at the end of the century the making of it was no longer allowed. It was made from the urine of cows fed only by mango leaves. At least this was the testemony of a Bengali researcher, send by the British, untill now it could not been confirmed.

In 1779, Vauquelin deduced that crocoite was a combination of lead and a new element, called chrome (from the Greek 'colour'). In the beginning of the century synthetic preparations from lead and chronium were invented. It gave intense colours from a golden yellow unto red. Very opaque, but with limited lightfastness and stability. It blackened and made the warm yellows of Van Gogh turned greenish. In the 1950s it was made lightfast. Modern lightfast chrome pigments (based on the monoclinic crystalline form) are encapsulated with silica and various metal oxides (as sold by Rublev.) Cinnabar green, a copper tartrate or copper arsenic used in the 18th century, was replaced in the first half of the 19th by a mixture of chrome yellow primrose and prussian blue.

In 1775 Scheele invented a replacement for verdigris, called Scheele's green. It is sometimes discoloured by acids and sulphurs. In 1808 emerald green was developed to improve Scheele's green, copper aceto-arsenide. Being very brilliant, it still got brownish when in contact with sulphur, as in cadmiums or ultramarine. It was made by reacting verdigris with arsenic compounds. Unfortunately it was also used as food colourant and in households. It may have been responsible for death of children by use in wallpapers. This pigment was banned only since the 1960's.

Cobalt blue was mined for pigment since antiquity, not exactly the same as we use today. The name is derived from cobolt, the creatures held responsible for tormenting the miners, which was rather caused by the presence of arsenic. In 1802 it was synthetised by Thénard in 1802. In combination with other elements it can be made into green, violet and yellow. Cobalt green was discovered in 1780, the alumina was replaced by zinc oxide. Cobalt violet is manufactured from 1859. Cobalt yellow was made in 1831, but only available from the 1850s. Impressionists and neo-impressionists used cobalt colours abundantly.

In 1828 Giumet perfected the making of artificial ultramarine by heating china clay, soda ash, coal, charcoal, silica and sulphur, called French ultramarine. Ultramarine violet is made by heating ultramarine blue and ammonium chloride. Heating it with hydrochloric acid, ultramarine pink was made.

Cadmium is extracted from zinc ores and where very popular with impressionists. Cadmium yellow is made from cadmium sulphide, ranging from lemon and intense yellow to orange. Discovered in 1817 it became commercial but from 1840 because of the scarcity of the metal. With the addition of selenum, cadmium red is created, introduced from 1910, light red to dark, replacing quickly vermillion. (Some painters still prefere the more delicate and less dominant vermilion.)

Impressionists also used abundantly cerulean blue, a mixture of cobalt and tin oxides, cobalt stannate. After Egyptian blue disappeared and the name was given to other blue's, it was discovered by Höpfner, but forgotten again and rediscovered in the 1860s. There is also a greener version in which the tin is replaced by chromium, often called cobalt turqoise.

Manganese violet was discovered in 1868, and preferred by some artists, giving stronger violet than cobalt but it is not the best lightfastness. Manganese blue was weak and didn't have any success.

The method of manufacturing synthetic iron oxides was known from the 15th century, but became only commercial from half 19th century. This replaced the natural digged earth colours, often called Mars colours. The purest hue's where created by precipitation and hydrolysis of iron salt solutions. They are currently more stronger, opaque and finer than most digged ones.

Lead white has been used a lot from antiquity untill the years 1960s. It is irreplacable and therefore still sold by some artist' branches. Because it contains lead it should be used with great care. It was also used a lot in wall paints and even cosmetics. Until the 19th century the nobel ladies used to rub it on the face to keep it pale and to resist age wrinkles, twice a day. Becoming old it resulted in a catastrophic decay.

The modern method of making zinc white, known as the French process, was perfected in 1844 and the pigment was expected to replace lead white. This caused a disaster in oil paintings since it glazes and brittles. Some modern art using much zinc white, has been repainted several times. Zinc white started it's career in 1834 in watercolour (where it is perfectly reliable) under the name Chinese white. Zinc oxide became commercial from 1835. Zinc white is often mixed with titanium white. Several branches do not even sell pure titanium, they always add the cheap zinc white. Even small amounts of zinc white still have the same disastrous brittleness in oil paintings, and even more when oil is used over an acrylic base. Zinc white in oils can only safely be used in top layers.

Uprise & domination of the petrochemical pigments in the 19th and 20th century

Synthetic titanium dioxide was used from the late 19th century. Natural titanium, found in the mineral ilmenite and discovered in 1791, was not used as a pigment because it was too contaminated with iron. Titanium white didn't have a lot of success, it was much more expensive then lead white, but in the years 1920 lead white became more and more forbidden because of toxity. Titanium white is much more reliable in oil painting than zinc, but it can be disastrous too, letting UV-light penetrating into the layers of the paint, affecting the other colours as well. Only the rutile process of making titanium white is safe for fine art (but over long times not with the same reliability as lead white).

In the 19th century, one discovery ofter another was done in the chemistry of dyes and pigments. In 1826 Robiquet isolated alizarine crimson from madder. Soon the synthetic alizarin ruined the market of the natural madder on several places. Unverdorben extracted aniline from indigo in 1826. In 1856 Perkin patented mauveine, a mauve, being the first synthetic dye. In 1860 Kekulé published a work in which he explained the moleculair benzene ring, later called aromatics (...HC=HC-CH=CH-C=HC-...) Organic chemistry was born, colour dyes became the base of great importance in the history of medicines. Soon synthetic dyes destroyed the market of cochineal. In 1904 Germany exported 9000 tons of synthetic indigo, ruining India and the Caribbean as well as the English indigo trade. Each year thousands of molecules where patented, not always of the right qualities. In 1880 thio-indigos, a violet, was discovered. In 1900 followed the quinacridones, ranging from orange red to violet red, because of it's lightfastness widely used in automobile paint (other quinacidrone tones are however cat II). Germany was the leading nation, the US started late and with help of the basic materials imported from Germany.

Artist's paint factory now could offer a new range of bright artificial colours, such as China green, aniline and Hansa yellows, red lakes, alizarin pinks, aniline browns...

However, modern colours where not always reliable. The pink geranium lakes Theo Van Gogh bought for his brother Vincent, turned pale blue, as did the rose lakes used by Gaugain. Methyl violet proved to be very fugitive. Ensor also used them in his pastels.

In the 18th century ready-made colours where for sale, but in fragile pig bladders. In 1841 J. Goffe Rand patented a tube made of tin sheet. Winsor&Newton improved the cap and brought the first tube colours on the market. In the 19th century additives came up, fats and paraffins. In 1918, the allies acquired Germany's patents of dyes as spoiles of war, which soon changed the industrial landscape. The US, England, France, Japan and Italy now became the mass exporters of synthetic colours. Chemical industries where founded all over the world, as in India, Australia and South Africa, German chemistry lost it's market.

In 1934 the copper-based phtalocyanines where discovered, producing intensive blue's and greens. In the second world war, the chemical factories also invented war-related product, such as chemical weapens, plastics and penicillin. C. 1950 BASF counted 350000 patents from which 3500 are still actively exploited. After the war, synthetic indigo became the top of all dyes, until it was replaced by phtalocyanine. New discoveries where the pearlescent and iridescent colours from 1980, flakes of mica coated in titanium oxide, and from 1990 coated with hematite. Colouring in food came up for giving the food a brighter look. For instance, fruit picked long before riping, is coloured to look tasty. Some natural colours, such as cochineal, sea archil, caramel and red ochre, where kept in use.

In the 1940s luminescent colours came up, glowing in daylicht (fluorescent lights up with ultraviolet light), widely used in art, but fugitive and not at all lightfast. Zinc sulfide superseded by strontium aluminate, giving a temporal after-glow when the lights are out.

Today

There never has been such a paradise of colour pigments for artist's as today, if you can afford them, and if you make a good search for quality. One can choose in petrochemic pigments for the most lightfastness, since most of them have now been tested and listed. Most of those colours in artist's branches are however cat. II or worse. If you are looking for earth colours, each one is made artificially. But you can still chose for digged ones from all over the world (as with Rublev). Antique pigments stay available and have a real come-back these days. In oils Rublev offers among others lazurite, azurite, vermillion, maya blue, several lead white's, vermillion, even orpiment and realgar (arsenic). Daniël Smith offers among others lazurite, malachite, tiger's eye, amazonite, porter's pink and in watercolour also amethyst. An economical war is still going on for the supremacy of synthetic pigments. In Europe the selling of leads and cadmiums are forbidden for reason of causing cancer. A good decision for common use, but exaggerated for artist's use (there are however strict rules of care to follow). Where leads are sold only for artists, they are highly taxed. In Europe, a lot of artist's brands mainly sell chemical pigments and mixtures with it. Since petrochemic colours are so dominating mixing the right colour becomes a difficult job for the artist. Also cleaning palette and brushes is not an easy job anymore.

The right information is not always given in each branch. And names are absolutely unreliable, for every one can give his colour the name he wants. Sometimes 'hue' is added for petrochemical replacement, or 'genuine' for the old colour, but also this is not garantied. So choosing the best and most suited pigments is not an easy job. One can rely only on pigment numbers.

We end with a short table of some organic artist colours of today with it's lightfastness. They are often transparant, so suited for glacis or mixing with opaque colours.

Increasing damage is found in painting of well-known painters since the 60s, and artist's paint got even worse after 2000. Various damage are caused by additions. Water sensibility (caused by the metal stearates), dirt deposition, efflorescence, softness of painted layers, craquelure, detachments and wrinkles, paint being brittle and fragile, or sticky and soft. Efflorescence is also called haze, exudation, fatty acid deposit or migration, saponication, crystallization, chalking, mold, or ghost images. Several additives are found in artist's paints, such as lipidic binders, dispersion agents, stabilisers, extenders, fillers and driers. Fatty diacids, lipidic media such as semi- and non drying oils, pigments such as zinc white, and dryers play a crucial role in the vulnerability of the paint. That's why some branches offers paint without additives. Oil can pile up in these tubes, but there are tricks to solve the problem.

Egyptian blue is now used in the medical world in scanners because of it's radiating property. When red or green light shine on it, it glows infrared light.

Table of some organic, petrochemical pigments we find in artist's oil branches, based mainly on artiscreation.com. On the right the lightfastness. O = oil, a = acryl, wc = watercolour, NR is not rated by ASTM. For this also called synthetic organic pigments, one can find often on the right "lightfastness differs from branch to branch". So in this following short tabel, the lightfastness levels are only correct for the best of artist branches. It is very easy for a branch to replace the pigment with a cheaper one of the very same pigment number. Handprint.com for instance compares for phtalocyanineblue, all PB15, prices from 4 to 28 dollars a pound. Attention: also mixed with white has been tested at ASTM, but that is 'standard white', with mostly baryte white. For the few tested with titanium white, is proved cat. II, with lead white even III or IV.

Johan Framhout, 10th of December 2019