Archaeological discoveries

Ancient Egypt:the secrets of the painters of eternity

By analyzing, in situ , the chemical composition of Egyptian colours, researchers are renewing understanding of the artists' technique and the symbolism of these spellbinding images.

Copy of a fresco from the Temple of Memnon at El Kab in Egypt.

This article is from the Special Issue of Sciences et Avenir n°197 dated April-May 2019.

Golden yellow of the flesh of the gods, white of the light linen tunics, bright green of the vegetation reborn after the flood... Evoking a world of eternally young beauty, the frescoes which adorn the tombs of the ancient Egyptians seem as alive as they millennia ago.

A very limited number of pigments

"At first glance, their colors seem pure , remarks the chemist Philippe Walter, director of the Molecular and Structural Archeology Laboratory (Sorbonne University/CNRS), in Paris. But with a simple microscope, we see small green, blue, yellow specks in the dark red skin tones of men. The testimony of a true artistic will." With an international team including in particular the epigraphist Philippe Martinez, a research engineer in the same laboratory, he studied in situ twenty tombs in the Valley of the Nobles dating from the New Kingdom. The goal ? Better understand the evolution of Egyptian art, but also discern the helping hand and, why not, identify the personalities of artists. "Miniaturized techniques have revolutionized the study of monuments:there is no longer any need to take a fragment of the wall support. And digital photography makes it possible to obtain 3D views of the monument and to zoom in for unparalleled fine detail" , point out the researchers.

"We can see that the number of pigments is very limited for paints" , continues Philippe Walter. Black is simply carbon black; white, the limestone support, or even huntite, a luminous carbonate of calcium and magnesium. There are still brown, yellow and red earths tinted by iron oxides, deposits of which have been discovered in Luxor. Other pigments come from afar, perhaps from the Gulf of Aden:an orange-red, realgar; and above all a yellow, orpiment:a natural, golden, shiny arsenic sulphide, very suitable for the representation of divine flesh.

This article is from the Special Issue of Sciences et Avenir n°197 dated April-May 2019.

Golden yellow of the flesh of the gods, white of the light linen tunics, bright green of the vegetation reborn after the flood... Evoking a world of eternally young beauty, the frescoes which adorn the tombs of the ancient Egyptians seem as alive as they millennia ago.

A very limited number of pigments

"At first glance, their colors seem pure , remarks the chemist Philippe Walter, director of the Molecular and Structural Archeology Laboratory (Sorbonne University/CNRS), in Paris. But with a simple microscope, we see small green, blue, yellow specks in the dark red skin tones of men. The testimony of a true artistic will." With an international team including in particular the epigraphist Philippe Martinez, a research engineer in the same laboratory, he studied in situ twenty tombs in the Valley of the Nobles dating from the New Kingdom. The goal ? Better understand the evolution of Egyptian art, but also discern the helping hand and, why not, identify the personalities of artists. "Miniaturized techniques have revolutionized the study of monuments:there is no longer any need to take a fragment of the wall support. And digital photography makes it possible to obtain 3D views of the monument and to zoom in for unparalleled fine detail" , point out the researchers.

"We can see that the number of pigments is very limited for paints" , continues Philippe Walter. Black is simply carbon black; white, the limestone support, or even huntite, a luminous carbonate of calcium and magnesium. There are still brown, yellow and red earths tinted by iron oxides, deposits of which have been discovered in Luxor. Other pigments come from afar, perhaps from the Gulf of Aden:an orange-red, realgar; and above all a yellow, orpiment:a natural, golden, shiny arsenic sulphide, very suitable for the representation of divine flesh.

As for blue, the tombs only contain the famous Egyptian blue, close to lapis lazuli, and perhaps born… in Mesopotamia! "A pigment so fantastic that it will be used almost exclusively until the end of the Roman Empire throughout the Mediterranean basin:it is that of the frescoes of Pompeii!" , enthuses Philippe Walter. First synthetic pigment, it is obtained by heating a mixture of copper, sand, limestone and ash to 850 degrees. A few additional tens of degrees, and there it is transformed into green. "To obtain it, it was necessary to organize a real chemical industry" , says the scientist. An English Egyptologist, Gareth Hatton, calculated in 2008 that the decoration of a temple required 1,400 kilos of blue!

In Egypt, images were meant to confer eternity

Certain pigments, such as lazurite for blue, although known to the Egyptians, were never used by artists. Was this choice based on aesthetic or rather symbolic considerations? In Egypt, images are indeed always idealized, because they are intended to confer eternity, to magically revive what is represented. And color gives the appearance of life. "It is what is real, alive. A thing without color is not of this world" , points out Philippe Martinez.

In some cases, especially for plants, it only reproduces reality. But when it comes to expressing a theological conception, symbolism is never far away... The universe of blue-green, for example, is both abundant and coherent. "Texts say that the flesh of the gods is made of gold and their hair of lapis lazuli, probably with the idea that they are related to the sky and the air , explains Philippe Martinez. A green-skinned Osiris expresses the idea of ​​regeneration, and so does a mineral like turquoise, which we make offerings to be invigorated. As for the scepter ouadj, or stem of millions of years, a protective amulet in the shape of a papyrus stem, its very name means to rejuvenate, to re-green." Texts, color, material, lexicon thus all belong to the same symbolic sphere.

Another example is given by lapis lazuli, a very dark blue with gold and silver flakes. "During the New Kingdom, the glass industry developed, with a lot of work to get closer to this semi-precious stone and turquoise, perceived as divine and linked to the blue-green of regeneration , specifies Philippe Martinez. Now the roots of the words meaning glass and lapis lazuli are very close. Their symbolic connotations certainly are too. The glass craftsman would seek to recreate what nature, and therefore the gods, offer to humans". "Color can also code a function, an identity" , recalls Philippe Walter. Osiris is sometimes represented black, in obvious connection with his function as god of the underworld. But this color more often refers to the fertile land after the flood. Red is the color of the sun or the desert, of the wild, of the enemy, and of the hair of Seth, the evil god par excellence. White has a connotation of purity. As for pink, it is used "for things extraordinary in their perfection or beauty, like… horses or giraffes!", explains Philippe Martinez.

In the absence of texts, we can often only make assumptions, trying not to project the imagination of the Westerner of the 21 e century. "Why are men brown and women more 'yellow'? wonders Philippe Martinez. The classic explanation is that men, being outside, tan... But we don't know! Because when we examine the frescoes closely, we see that the yellow chosen is orpiment, used for gold, the flesh of the gods. The women represented belong to the high bourgeoisie, perhaps the yellow refers to the Golden one, that is to say to Hathor, the goddess of joy, of motherhood." The two scientists now hope to be able to build a real corpus allowing comparisons and further study. "In ten years, we will succeed in obtaining panoply of new data. The contribution of analyzes in situ simplifies the life of researchers in an incredible way!", concludes Philippe Walter.