We will continue to highlight the different types of pigments, emphasizing in their history from birth, evolution and new developments for our segment.
by Julián A. Restrepo R.*
This article began by talking about different historical aspects that were fundamental to the evolution of paintings. Subsequently, some types of pigments such as white, black, brown, yellow and red were listed. Now we will conclude by highlighting other pigments, resins and pointing out the final conclusions.
- Blue pigments: The Egyptians created, 10,000 years ago, the so-called Egyptian blue pigment (Pompeian blue or blue frit; CaCuSi4O10), mixing lime, silica, sodium carbonate, alumina and a copper mineral, such as malachite. Cerulean blue (cerulean or celestial), Mayan blue, copper carbonate (CuCO3), royal blue (name given to dyes produced from lapis lazuli), French blue (another historical name for overseas blue), crushed gemstones (aquamarine, lapis lazuli) were also used.
When the Maya offered a human being in sacrifice to the gods, they decorated his body with an intense and very resistant blue pigment, known as Mayan blue. To the amazement of scientists, this pigment is not affected by the passage of time or inclement weather. Not even acid or modern chemical solvents manage to affect it [24].
But how did the Maya obtain between 300 and 1500 AD.C. that indelible painting? According to new archaeological remains, the ointment was manufactured next to the Sacred Well of the city of Chichen Itza (Mexico) as part of the ritual sacrifices. "The sacrifices were intended to placate the rain god Chaak." Before starting the liturgy, the Maya heated indigo, incense and a clay called a paligorskite in a high-temperature container. The result was an almost indestructible bluish pigment, which experts have described as "one of mesoamerica's greatest artistic and technological achievements" [24].
On the other hand, formerly the most expensive color was the "ultramarine blue" (azurite or ultramarine), since it was obtained by spraying a semi-precious stone, lapis lazuli. Commissioning a portrait in which ultramarine blue was used was considered a great luxury, and it was frequent that its quantity, use and extension was subject to very precise specifications in the contracts made with the artist.
The Flemish painter Jan Van Eyck (fifteenth century) generally did not employ blue in his works. If a customer wanted blue, they had to pay extra [17]. The prohibitive price of lapis lazuli forced artists to look for less expensive alternative pigments, both mineral (azurite) and biological (indigo) [14]. While carmine was popular in Europe, blue remained an exclusive color, associated with wealth and prestige. Seventeenth-century painter Johannes Vermeer frequently made luxurious use of lapis lazuli, along with carmine and Indian yellow, in his colorful paintings.
Due to the cost of lapis lazuli, many attempts were made to find a less expensive blue pigment. Prussian blue was the first modern synthetic pigment, discovered by accident in 1704. By the early nineteenth century, synthetic and metallic blue pigments had been added to existing varieties of blues, including French ultramarine (a synthetic form of lapis lazuli), and the various forms of cobalt blue and cerulean. At the beginning of the twentieth century, with organic chemistry, phthalocyanin blue was added, a synthetic organic pigment with an enormous dyeing power [14].
- Violet pigments: Cobalt violet, Tyrian purple (imperial purple or ancient purple), Chinese purple (Han purple).
Tyre purple was a pigment produced from the mucosa of a snail of the genus Murex. Its production began from at least 1200 BC.C. with the Phoenicians, and was continued by the Greeks and Romans until 1453 AD.C., the year of the fall of Constantinople. Pigment was expensive and difficult to produce, and objects dyed with it were synonymous with power and wealth [25].
In such mollusks, the precursor fluid of the dye is found in a gland near its head, and is initially whitish. This was extracted by pressing the snails, and by the effect of air and light changed color, becoming pale yellow, until it became purple; the final color of the dye was unalterable in the light. Each mollusk gave only a drop of dye, so obtaining thirty grams of dye demanded about 250,000 snails (which would currently be equivalent to about 125,000 euros, only in raw material), justifying the very high price of purple-dyed cloths.
Throughout the Mediterranean legions of fishermen collected Murex for the factories and in the vicinity of these have been found authentic hills formed with the shells of discarded snails. The stench that gave off the elaboration process made it take place far from the cities but, due to the secrecy maintained by the manufacturers, little or nothing is currently known about the technique followed to obtain the dye [15].
Her story, according to Greek and Roman mythology, relates that Helena was walking with her dog on the beach of Troy, where she remained captive. The dog began to nibble on a snail that was on the beach and the muzzle was stained with a beautiful and unknown color similar to an intense violet that caught Helena's attention. Bewitched by that wonderful color, she had a dress dyed with it, beginning the incredible story of purple [15].
According to another similar Phoenician legend, it was the god Melgart and the nymph Tyrus who made the discovery on a beach in Tyre [26]. In any case, whether it was Thyrus' dog or Helena's, the substance whose origin the ancients narrated was for almost two millennia the most expensive product in the world, even more than gold, and today, several millennia later, it remains unique [15].
According to tradition, Helen of Troy was the one who enjoyed, for the first time, the luxury of wearing purple.
- Resins: Binders and resins have an equally past history. Since ancient times, materials such as animal fats, vegetable gums, starch, milk, eggs, beeswax, gum arabic, glue, gelatin, fish (product of the distillation of tar or turpentine, also known as pitch), shellac, sap of various trees, balms, insect secretions ("lac insects"), natural drying oils, among others, were used. Also, various technological advances were made by the Egyptians 5,000 years ago who used casein to improve the adhesion of their paintings [12].
The resin secreted by a small red insect (lacquer worm or Kerria lacca), cooked was used to create shellac more than 3,000 years ago in Southeast Asia. The resin of the varnish tree (Japanese Sumac) was used to make Japanese lacquer 2,000 years ago [12,27]. The lacquer worm lives and feeds on trees found in the rainforests of these countries and exudes a hard shell-like material. Local growers collect the coated twigs and remove the shell-like material from them. This residue is subsequently crushed to form granules, placed in tissue sacs and heated over an open fire until the material begins to soften and finally melts.
But it wasn't until the 1930s, that the science of heavy polymers began to emerge, and the greatest growth of the technology of these materials came later. Even today, the dimensions of polymers are no longer forgotten, given that the industries associated with polymer materials employ more than half of the chemists and chemical engineers in the US [28].
Final comments
We can affirm that the history of paintings is the history of art, if we consider their omnipresence in various activities of human life since ancient times: Used for the ornamentation of their bodies, in ceremonies, decorate their homes, as well as they were attributed a mystical or religious sense; they were used in the preparation of sarcophagi, for the decoration of ceramics and in the elaboration of decorative murals, among others.
Likewise, the accident rate in the development of various pigments and in the identification of associated toxic substances has allowed the evolution of this industry to this day. This is how we have seen the replacement of pigments based on heavy metals by less toxic pigments (white lead by titanium dioxide, for example). It is therefore curious to recognize that in the world of paintings, like many other sciences, many advances were obtained accidentally.
As for its technological development, we know that solvent-based paints were the main consumption until the mid-twentieth century, since the main source of raw materials was oil. Per se, today, among the new technologies of alternative paints, water-based paints are among the options to solvent-based paints, since they have a lower content of VOCs -volatile organic compounds- (or practically zero in some cases), and are more friendly to the environment, being therefore, among the paintings of the past, present and future (which can be analyzed from the point of view of the so-called idea of the "Eternal Return") [11], since they are watery paintings already used by our prehistoric ancestors.
References
[11] Restrepo, J.A., "The Idea of eternal return, part I." Revista Inpralatina, Vol. 17, No. 3, May/June 2012, pp. 37-38.
[14] http://es.wikipedia.org/wiki/Pigmento
[15] http://labitacoradehumboldt.blogspot.com/2010/11/purpura-de-tiro.html
[17] (a) Behan, J., "The Bug That Changed History"; Grand Canyon River Guides; b) Pastoureau, M., "Blue: The History of a Color". Princeton University Press, 2001.
[24] http://www.muyinteresante.es/historia/articulo/la-receta-secreta-del-qazul-mayaq
[25] a) Theopompus, quoted by Athenaeus in the s. 200 a.C.; according to Gulick, Charles Barton (1941). Athenaeus, The Deipnosophists. Cambridge: Harvard University Press; b) http://es.wikipedia.org/wiki/P%C3%BArpura#cite_note-Heller-16; c) Heller, E., "Psychology of color", Barcelona: Gustavo Gili. p. 195, 2012.
[26] http://www.andinia.com/articles/artes_pasatiempos_y_artesanias/a04870.shtml
* M.Sc. Ph.D. Julián A. Restrepo R. PMC Technical Manager of PPG Industries Colombia, [email protected]
Leave your comment