Belgian physicists have found that the stain in Edvard Munch's painting "The Scream" is wax, and not bird droppings, as previously thought. The conclusion is simple, but to reach it, complex technologies were needed. In recent years, the paintings of Malevich, Van Gogh, and Rembrandt have been revealed to us from a new side thanks to X-rays and other scientific instruments. Pavel Voitovsky tells how physics turned out to be at the service of lyrics.
Edvard Munch wrote four versions of The Scream. The most famous is in the National Museum of Norway in Oslo. As luck would have it, in the most prominent place of the masterpiece there is a blot. Until now, there were two main versions of the origin of the stain: it was bird droppings or a sign left by the artist himself.
The second version turned out to be easier to check. For this purpose, scientists from the University of Antwerp in Belgium used the MA-XRF X-ray fluorescence spectrometer. The picture was irradiated with x-rays and the reflected energy was measured, unique for each element of the periodic table. At the site of the blot, no traces of lead or zinc, which were present in the whitewash of the beginning of the century, or calcium were found - this means that the stain most likely was not part of Munch’s plans.
However, the first version with bird droppings was considered by art critics to be much weaker. Not because it is ugly, but for strictly scientific reasons: droppings corrode the paint, which is not noticeable in Munch’s painting. To put an end to the dispute, a fragment of the blot was taken to Hamburg and placed in the DESY synchrotron, the largest particle accelerator in Germany. The technique is based on X-rays again, but the phenomenon of diffraction rather than fluorescence is used. Atoms of different elements refract X-rays differently. By comparing the refraction graphs of three substances—bird droppings, candle wax, and a spot in a Munch painting—the researchers obtained the same picture in the second and third cases. Thus, the reputation of the great Norwegian was cleared: birds were not involved in the matter, wax was simply dripped onto the famous canvas in Munch’s studio. If we had known that it would cost $120 million (that’s how much the early pastel version of “The Scream” was sold at Sotheby’s in 2012), we would have been more careful.
The study of art today is possible using a range of sophisticated tools, from carbon dating and lasers to fluid dynamics and the short pulses of light that allowed Pascal Cotte to reconstruct an early version of the Mona Lisa. We must not forget about the capabilities of the computer: engineer from Texas Tim Jenison, using 3D modeling, completely recreated Vermeer’s painting “The Music Lesson”. The American wanted to find out how the artist managed to create such realistic images. The researcher came to the conclusion that Vermeer used a complex system of mirrors. In fact, he created photographs a century and a half before the discovery of photography.
Recreation of Vermeer's "The Music Lesson" in real scenery with live actors
And yet it is x-rays that bring the most interesting results. In recent years, it has led to the birth of an entire discipline that can be called “pictorial archaeology.” Time after time we learn almost detective stories about the secret past of the paintings. For example, in a 17th century Dutch painting a whale was found washed ashore!
And in a painting depicting an experiment at the court of Queen Elizabeth, an x-ray revealed skulls around the figure of John Dee, the great British scientist of the 16th century. An ominous detail reminds us that John Dee was also known as a magician and expert in the occult sciences. Apparently, this was too much for the customer of the painting, and he asked the artist Henry Gillard Glindoni to paint over the skulls.
In Russia, the most famous study of this kind was discussed last year. The Tretyakov Gallery announced the opening of two color images under Malevich’s “Black Square”.
In addition, scientists discovered fragments of the author's inscription on the painting: a word starting with n and ending with ov. The whole phrase, according to museum staff, sounds like “The battle of blacks in a dark cave.” Perhaps in this way Malevich recognized the merits of his predecessor: a comic painting of a black rectangle with a similar name was created in 1893 by Alphonse Allais. But what’s more important is that the uncompromising suprematist suddenly demonstrated a sense of humor - and became a little livelier for us.
The discoveries of “scientific art criticism” humanize great artists. Van Gogh, out of poverty, reused canvases, Picasso was the first to use ordinary building paints rather than oils, and Munch exhibited paintings in an open courtyard, where they could easily become victims of a flying bird. Or, let’s say, there is such a trend as the study of eye diseases of painters. Could Impressionism have been born from the simple fact that Monet suffered from cataracts? Could El Greco paint elongated figures due to astigmatism (a deformed lens)? Similar questions are asked, among others, by the authors of the book published in 2009 "The Eyes of Artists" WITH Let me tell you, this is a rather unexpected look at the history of painting, which an art critic will not like, but for us it can make the picture closer.
Sometimes X-rays directly hit the critics’ vanity. Entire volumes have been devoted to the symbolism of the unicorn in Raphael’s painting “Lady with a Unicorn.” But the scientist from Florence Maurizio Seracini discovered that the fantastic creature was originally just a small dog. Moreover, the pet was most likely added after Raphael. Articles on symbolism will have to be rewritten.
Another example: Rembrandt’s “Danae” originally resembled the artist’s wife Saskia. After the death of his wife, the painter brought the heroine’s facial features closer to the image of his new passion, Gertier Dirks, in order to overcome her irrepressible jealousy. Thousands of visitors to the Hermitage pass by"Danai" every day, not knowing what is in front of them— the plot is not only antique, but also quite everyday.
Early and late Danaë in Rembrandt's painting
I’ll end with my favorite example of painting research. True, X-rays and microscopes were not needed here - only the meticulousness of the scientist and work in the archives.
In 2014, the Observer published a story by Andrew Scott Cooper, an employee of the San Francisco Museum of Modern Art. For seven years, Cooper studied Robert Rauschenberg's collage "Collection 1954/1955". The picture was painted at the height of the “witch hunt”, which affected both communists and gays: there were mass layoffs and police raids. The historian was interested in whether Rauschenberg could have exchanged secret messages through the painting with his lover Jasper Johns, another icon of post-war American art.
"Collection 1954/1955" by Robert Rauschenberg
Cooper knew that the most talked-about news of the second half of 1954 in New York was the high-profile trial of four gay Jewish teenagers. They were accused of serial attacks and murder. And then, under the layers of paint in Rauschenberg’s painting, the historian discovered an editorial from the New York Herald Tribune newspaper for August 20, 1954. From the archives it turned out that on that day the scandal with hooligans was discussed in detail on the front page. In addition, the artist highlighted the word plot(“conspiracy”) from an extraneous title.
Fragment of newspaper titleNew York Herald Tribune in a painting by Rauschenberg
Research into Rauschenberg's painting led Cooper to become seriously interested in the teenagers' case. He pulled up the New York State archives and discovered many inconsistencies. Soon, after a full-fledged investigation and an interview with one of the participants in the events, the journalist came to a clear conclusion: the four teenagers were unfairly accused. They did carry out attacks, but most of the cases were simply “blamed” on them - the hooligans turned out to be victims of a political order to denigrate homosexuals. Rauschenberg guessed this when he painted the picture, and encrypted the truth in his collage.
Thus, the study of an abstract painting indirectly led to the establishment of justice. And art fans were once again reminded how multi-layered paintings are and how closely the artist’s life is intertwined with his creations.
One of the most famous paintings in the world - the portrait of Mona Lisa by Leonardo da Vinci - never ceases to interest researchers.
In 2015, the Frenchman Pascal Cotte reported the results of studying the painting using his own proprietary method. He used the so-called layer amplification method: bright light is directed onto the canvas several times, and the camera takes pictures, recording the reflected rays. After this, by analyzing the resulting images, you can study all the layers of paint.
- globallookpress.com
- Daniel Karmann
According to the researcher, under the portrait that is visible, there is another one hidden - and there is no smile on it: Kott was able to see a larger head, nose and hands. Moreover, he stated that there are more than two layers in the picture, and supposedly in one of the first versions you can also see the Virgin Mary.
Researchers at the Louvre, where the portrait is kept, have not commented on the alleged discovery. Other researchers have expressed doubts about Kott's findings. They are inclined to believe that there were no fundamentally different images on the canvas, the Frenchman simply managed to consider the different stages of work on one portrait. So, da Vinci, who painted a painting to order, could change it at will or at the request of the customer.
Portrait under flowers
At the end of the 19th century, Vincent Van Gogh painted the famous painting “Patch of Grass”. Surprisingly, it also revealed an earlier layer of paint under the lush greenery.
- Wikimedia / ARTinvestment.RU
It turned out that the portrait of a woman, made in brown and red tones, was the first to appear on canvas. This incident hardly surprised scientists: it is known that Van Gogh was not recognized during his lifetime and, due to financial difficulties, often painted new paintings on top of old ones.
From an enchanted pose to philosophical motives
Belgian artist Rene Magritte's painting "The Enchanted Pose", painted in 1927, was considered lost five years later. Much later, an employee of the museum in Norfolk carried out a proper check before sending the painting “Man’s Lot” to the exhibition. On the edge of the canvas she noticed paint that did not fit into the overall color scheme. Then X-rays came to the rescue - thanks to it, researchers often determine what is under the top layer of the picture.
As it turned out, “The Human Lot” was written on top of one of the fragments of “The Enchanted Pose” - the creator cut it into four parts, and three of them have been discovered today. Art critics find consolation in the fact that, at least, Magritte did not simply destroy his creation, but painted several more works on its remains that were worthy of public attention. The sad thing is that a partially found work of art cannot be separated from later works. The reasons why the artist decided to deal with his painting also remain a mystery.
What's hidden in the Black Square?
Art historians at the Tretyakov Gallery have found hidden images under one of the most recognizable paintings in the world - “Black Square” by Kazimir Malevich. The artist hid the inscription under black paint. It was deciphered as “battle of the blacks at night.” As for the painting, which Malevich probably first tried to create, what was painted on it was able to be partially restored. The earliest and most thorough layer of paint compared to later ones represents a work that, according to researchers, is close to the author’s cubo-futuristic works.
- RIA News
It should be noted that at first the picture was much brighter than the final version. The painted image was discovered back in the early 1990s. At the same time, quite a lot of methods were used that made it possible to draw such conclusions. The painting was studied in the infrared and ultraviolet spectrum, macro photography and X-ray photography was carried out, and the pigment was analyzed using a microscope. Nothing is known about the reasons that prompted the author to create a black square on this particular canvas. The main versions of art historians boil down to the fact that in the process of work the artist’s plan gradually changed.
Continuous transformations
Individual elements in the paintings changed no less frequently. For example, the story of one of Raphael’s paintings is truly amazing.
- Wikimedia
Around 1506, Raphael Santi painted a portrait of a girl with a dog in her arms. And then, many years later, he painted a unicorn on top of the dog (scientists saw the dog by X-raying the picture). But the main thing is this painting, known as “The Lady with the Unicorn”, previously generally called “St. Catherine of Alexandria”. The fact is that after the death of Raphael, other artists added the attributes of a martyr to the “lady” and provided her with a cloak. It was only in the 20th century that scientists removed the finished layer and restored the painting. True, the unicorn remained in the hands of the “lady”: according to experts, attempts to get to the “original” dog are very risky and can lead to damage to the work of art.
Modern art historians are increasingly resorting to studying paintings by old masters using fluoroscopy, using the well-known property of lead white: to block x-rays. An X-ray image obtained by transilluminating a particular painting can show compositional changes made by the artist, alterations of individual details of the painting, corrected errors and other features of the artist’s technical process.
Using this method, it was established, for example, that the Dutch painter Rembrandt, when creating “Self-Portrait” in 1665, initially made a mistake by giving a mirror image of himself on the canvas: he had a brush in his left hand and a palette in his right. The artist noticed this only after the painting was completely finished. Having covered his hands with a thick layer of paint on the canvas, he painted them again. Now the brush was in the right hand, and the palette in the left.
Second example. The Flemish painter Rubens (1606-1669) changed the original composition of his painting "Portrait of Francesco Gonzaga" (kept in the Kunsthistorisches Museum in Vienna) after it was completed. Compositional changes are clearly visible in the above x-ray.
Also, quite recently, with the help of X-rays, it was possible to find out which of the two paintings by the artist Van Dyck “Saint Jerome and the Angel” (on the title of the article) is genuine, and which is just a copy (albeit an excellent one).
P.S. Perfume says: And when studying some old paintings, you can be surprised to discover that their paints contain the same components as maxilift cosmetics. Maybe this is the secret of the quality and durability of this cosmetics? By the way,
MUSEUM LABORATORY Laboratoire de musee. A service that conducts scientific, physical and chemical analyzes of paintings.
A museum laboratory should not be confused with a restoration workshop, with which they are in more or less close contact, depending on the country and institution. The results obtained by scientific methods make an important contribution to the knowledge of a work of art; they make it possible to accurately analyze the material side of a painting, which is so necessary both for storing a work of art and for the history of painting techniques. Scientific photography, radiography and microchemical analysis (we name only frequently used methods) seem to reveal the secret life of a painting and the stages of its creation, making visible the first sketch, registration and subsequent changes; they provide the necessary information to restorers, connoisseurs, historians and art critics.
Story
In France, the interest of scientists in the preservation and study of painting arose in the second half of the 18th century. among encyclopedists. The physicist Alexandre Charles (1746-1822), whose laboratory was located in the Louvre in 1780, was. probably one of the first scientists who tried to study the preservation and technique of the painting using optical instruments. In the 19th century Chaptal, Geoffroy Saint-Hilaire, Vauquelin, Chevrel and Louis Pasteur, in turn, devoted their research to the analysis of the components of paintings.
In England, the scientist Sir Humphry Davy (1778-1J29) also tried to analyze paintings and their constituent substances. In the second half of the 19th century. German scientists also became interested in these problems. The first research laboratory was created in 1888 at the Berlin Museum. Seven years later, the physicist Roentgen attempted to make the first x-ray photograph of the painting. At the beginning of the 20th century. The chemical method was improved, and in France, scientific work was resumed in the Louvre in 1919. However, it was only after the first international conference, which took place in 1930 in Rome, that the world witnessed the true beginning of scientific work. Among the services that existed by that time, mention should be made of the laboratory of the British Museum (established in 1919), the Louvre and Cairo Museum (1925), the Fogg Art Museum in Cambridge (1927) and the Museum of Fine Arts in Boston (1930).
Somewhat later, laboratories were created at national or municipal museums: the Central Laboratory of the Museums of Belgium (1934), the Max Dorner Institute in Munich (1934), the laboratory of the London National. gal. and the Courtauld Institute (1935), the Central Institute for Restoration in Rome (1941). Since 1946, similar services have existed in most major museums in the world in Poland, Russia, Japan, Canada, India, Sweden, Norway; other laboratories are still being created.
Scientific methods
Optical research, expanding the capabilities of vision, allows us to perceive what was previously barely noticeable or completely invisible. Nevertheless, studying a painting in natural light is a necessary preliminary stage of laboratory research, as is photographic recording. Traditional methods of photography have recently been supplemented with our own technologies for the scientific study of paintings. Light falling tangentially. A painting placed in a dark room is illuminated by a beam of light parallel to its surface or forming a very small angle with it. By changing the position of the light source, you can highlight different sides of the painting surface. Visual inspection and photographic recording of the painting from this angle indicate, first of all, the safety of the work, and also allow us to determine the artist’s technique.
It should be noted, however, that such a view of the picture distorts reality, and therefore the understanding of the information received must be accompanied by an analysis of the original.
Monochromatic sodium light. In this case, the picture is illuminated by 1000 W lamps, emitting only yellow light located in a narrow band of the spectrum. This results in a monochromatic appearance of the work being examined, which reduces the color impact on the retina and allows for an accurate reading of the lines. Monochromatic light removes the effect of foundation varnishes and allows you to read otherwise invisible inscriptions and signatures. You can also see the preparatory drawing, provided that it is not hidden by too thick a layer of glaze. The results obtained are less rich in data than those provided by infrared radiation, but the advantage of this method is that it can be used in visual analysis of the picture.
Infrared radiation. Thanks to the discovery of infrared radiation, it became possible to photograph what seemed invisible, but the results of this analysis can only be perceived by the human eye with the help of a photographic plate. Infrared rays reveal the previously unnoticed state of a work of art by absorbing or reflecting the color matter that makes up the painting. A photograph reveals to us an inscription, a drawing, an unfinished stage of work that is invisible to the eye. However, the results are unpredictable, and deciphering the image obtained in a photograph is often very complex and difficult. Nevertheless, it becomes possible to read the inscriptions sometimes located on the reverse side of the painting. In addition, infrared radiation makes it easier to determine the nature of the pigment, complementing the results of observations made under a microscope or physicochemical method.
Ultraviolet radiation. Under the influence of ultraviolet rays, many substances that make up the painting emit only their inherent glow; The results of this analysis can be photographed. The phenomenon of fluorescence is not only a consequence of the chemical composition of the dyes, but also depends on their age, which can lead to a difference in the colloidal state. The use of ultraviolet rays is of great interest not so much for the history of art itself, but for determining the safety of paintings. Old varnish coatings in ultraviolet radiation appear as a milky-colored surface, on which later registrations appear in the form of darker spots. Deciphering the obtained data is not easy and most often requires additional microscopic analysis of the surface, which will confirm or refute the hypothesis about the rewritten place, about the removal of varnish, or about traces of these damages, which are often very difficult to determine from photographs. However, this method is necessary for the restorer and allows him to assess the extent of previous restorations.
Macro and microphotography. These are photographic techniques often used when examining paintings. Macro photography magnifies the visible image (the magnification scale is very rarely greater than 10x) using a short focal length lens. It can be carried out in natural light, as well as in various lighting (monochromatic, ultraviolet, tangential). It allows you to isolate certain parts of the picture from their context and draw attention to these details. A microphotography is an image of a fragment of a painting obtained using a microscope. It records changes, invisible to the eye, in the state of a small area of the picture plane, sometimes not exceeding several tens of square millimeters. It also allows you to observe the condition of the varnish layers, the distinctive features of craquelure and pigments.
Microsections. This method is similar to that used in medicine for histological sections. Here, polyester resin is used to coat the test sample. After adding a small amount of catalyst and accelerator, the monomer polymerizes at normal temperature. The result is a solid and transparent mass, similar to glass. This mass is cut in such a way as to obtain a cut in a plane perpendicular to the plane of the paint layers; The flat section is then polished using aluminum oxide in the form of an aqueous suspension as the grinding material. The production of cross sections has been mentioned in various works over the past sixty years.
Electron microprobe. Its use solves several problems at once. This method, which satisfies the size criterion (micrometer) and allows an accurate analysis, can be used, in particular, when studying sections of a painting; a polished surface or thin section; an electron beam of light can examine layers of different composition, the thickness of which is several micrometers, and the elements mechanically inseparable. Inside each layer, a microprobe allows one to determine the elements that make up each material, and the resolution of this method far exceeds that of the best optical instruments.
Radiography. X-rays were first discovered in 1895 by the physicist Roentgen, who a few years later in Munich made the first X-ray photograph of the painting. In France, similar experiments were carried out only during the First World War, in 1915, by Dr. Ledoux-Lebard and his assistant Gulina. The work was continued at the Louvre in 1919 by Dr. Cheron. Systematic research began in museums only a few years later: in the Louvre - in 1924 (Celier and Gulina), a little later at the Fogg Art Museum (Burrows), in England (Christian Walters) and Portugal (Santos). After World War II, radiography became the most commonly used method of analysis.
Laboratories use weak X-rays. Generators are most often anti-cathode tungsten lamps, similar to those used in medicine. There are also devices for very weak radiation with lamps with a beryllium window and water cooling. The X-ray films are placed in a black paper envelope and can come into contact with the painting without risk. The clarity of the resulting image depends in part on the degree of contact of the film with the surface of the painting. X-rays recreate the invisible appearance of the painting. However, if the base of the painting is thick and the ground is of high density, then the internal structure of the picture may be difficult to read, but if radiation passes through the canvas and ground easily, then the paints used for the preparatory drawing, usually on the base, are easily revealed and thus the state of the picture, invisible to the eye, is revived , a stage of creativity previously inaccessible to perception. The first stage of work is not always visible on an x-ray. So, for example, in the photograph of E. Lesueur’s painting “Muses,” a complex combination of the first and second stages of work is revealed; the face is visible simultaneously in profile and from the front. If, on the contrary, the picture was painted with colors of low intensity and then covered with wide glazes, we will not see this first stage at all. The painting is subjected to X-ray analysis in order to infer the condition of the painting in anticipation of restoration or for purposes of interest to art historians. But the most accurate results from radiography can be expected in determining the composition and condition of the base.
The basis. The base is a wooden or copper board or canvas on which a layer of paint is applied. When it is necessary to examine a painting painted on copper, which, however, is rare, radiography cannot help, since the weak X-rays used in the analysis are not able to pass through the metal. However, if rays of greater penetrating power are used, they will not provide any information about the paint layer itself. In this case, only a study of the picture in infrared and ultraviolet rays can bring some clarity. When we are talking about a painting painted on wood (and there were a majority of such paintings before the 17th century), studying the properties and structure of the wooden base, visual inspection of which is often difficult, can be extremely useful. The wooden base is hidden on one side with a layer of paint, and the artist himself sometimes covers the other side with primer to avoid moisture. This primer is usually one-color or marbled. When the paint layers and soil are permeable to X-rays, an X-ray image of the wood base can be obtained.
Radiography makes it possible to trace the results of actions performed on a painting and to detect the technical means and techniques used by primitive artists. Thus, in an x-ray photograph you can see pieces of rough canvas included in the ground so that the joints of the boards do not appear on the paint layer itself. Raw fiber mixed with lime mortar is used in many 14th century paintings. In the 17th and 18th centuries. paintings, as a rule, were painted on canvas, which was then duplicated, that is, additionally reinforced with another canvas; this canvas (usually late 18th or 19th century) does not allow the original support to be seen. Duplicated canvas, provided that it was not impregnated with white during priming, does not pose a particular problem for X-rays.
The characteristics of the canvas depend on the country and era where and when the work was created. Thus, Venetian canvases most often have a woven pattern; Rembrandt used simple canvases. Thanks to x-rays, all tissue features can be determined. X-rays detect not only the type of canvas, but also the inserts in them. An x-ray allows you to evaluate the extent of changes (extraordinary or cropped pictures).
paint layer. X-ray examination of the paint layer of a painting allows us to solve some problems of its preservation. Derelict areas often occupy a much larger area than those in need of restoration. Thus, to hide a loss of several square millimeters in area, recordings of several square centimeters are often made. By comparing an ultraviolet photo showing the records and an x-ray showing the loss itself, it can be determined whether the replacement area accurately covers the loss. It should be noted that on an x-ray, the loss of the ink layer appears black or white. If they are covered with a thin layer of paint, they will be darkened, and the structure of the canvas or the wooden base of the painting will be clearly perceived.
On the contrary, when the losses are sealed with mastic, they will not let the rays through and form a white zone. Losses are also revealed by the appearance of areas where the canvas appears more clearly than in the rest of the picture. In addition, radiography allows you to study the main elements of the painting from the point of view of art history and technical techniques. In order for the painting to be visible, it is necessary to expose the soil, which is located between the base and the paint layer, to X-rays. In most cases, the wooden or canvas bases of paintings are permeable, with the exception of those that are reinforced on the reverse side. Whitewash, which is often included in artists' palettes, is made from heavy metal salts; Lead white creates a barrier to X-rays. Black paints, on the contrary, have very low density. Between these two extremes are colors that vary in intensity, which is why the X-ray image is subtly nuanced.
When the preparatory drawing is executed in the grisaille technique, consisting mainly of white, sometimes tinted, very interesting x-ray photographs can be obtained. If the preparatory drawing is painted with low-density paints, it is almost invisible; Only the general composition of the picture is visible.
When a painting is painted with glazes, the image, although visible, is not of contrast; this is the case with some paintings by Leonardo da Vinci. Many artists have used techniques that fall between these extremes. When the artist remade the painting, rewrote some of its parts in order to give them a finished form, different from the original (it was discovered by X-rays), then they talk about registrations (see). Registrations are very different. Some almost repeat and refine the original lines, and this is the most common case.
In the XIII-XVI centuries. artists usually executed their canvases only after they had worked out the preparatory drawing with exceptional precision, and therefore very few discrepancies between the preparatory drawing and the completed painting are found. At the same time, these artists worked with paints with a fairly low density - X-ray photographs most often have barely any contrast. X-rays are intended to be of great assistance in studying the style and manner of an artist. If x-rays of paintings by the same artist reveal the artist's consistency in the choice of pigments and brushes and in the form of strokes, then erroneous attributions can be corrected, chronology can be clarified, and forgeries can be detected. By fakes we mean only those paintings that are executed in order to mislead. Fakes should not be mixed with copies or old replicas, which should only be correctly attributed. But counterfeit elements that are present in the original painting itself (fake craquelure, signatures) can be detected using radiography, because the copyist and forger strives to reproduce only the surface of the works he imitates.
Microchemical and physicochemical analysis. To the mentioned methods, often used in museum laboratories (since they have the advantage of not destroying the painting), one should add microchemical methods, which make it possible to establish the constituent elements of the painting based on a microsample. It is known that paint consists mainly of pigment dissolved in a binder or solvent. Microchemical analysis of pigments, mineral or organic, falls within the purview of traditional microchemistry when it comes to mineral substances. In addition, it uses infrared spectrography and chromatography for some organic pigments.
The analysis of the binder is carried out in a similar way. Infrared spectrography is also used for the analysis of natural resins, and chromatography for the isolation of aqueous solvents (gum, glue, casein). Chromatography in the gaseous state is used to separate the constituents of various fatty acids (oil, egg). Among the methods used in museum laboratories are diffraction and x-ray fluorescence, which, in comparison with the above methods, make it possible to obtain more accurate data regarding the nature and structure of the various mineral components of easel and wall paintings. X-ray fluorescence is based on analysis of the emission spectrum in the X-ray region. The sources can be a stream of electrons, a radioactive source, or a beam of X-rays. X-ray spectrometry is used in both physical and chemical aspects. But the instruments used today are not designed for direct analysis of bulky or very small objects. In addition, most of them have low sensitivity to elements such as copper, zinc, nickel and iron, due to the “background noise” produced by the equipment itself.
X-ray microfluorescence, developed at the Laboratory of Scientific Research of French Museums, was created taking into account all the specifics of museology. Its parameters are located between the parameters of an electron microprobe and a conventional X-ray fluorescence spectrometer. Its advantages are that it allows research to be carried out directly on the painting without destroying it, that the sample can be reused for another analysis and that it does not require pre-treatment of the sample; it is extremely reliable, very sensitive, and relatively simple. All these methods require special equipment and personnel.
There are only a few museums and national services in the world capable of carrying out this kind of research; although, of course, as years pass, the traditional criteria for analyzing paintings will change under the influence of scientific advances, which should lead to a deeper knowledge of painting.
Application of methods. Preservation and restoration
Analysis of the materials from which paintings are composed, knowledge of the laws that determine the interaction of these materials with each other, on the one hand, and with the environment, on the other hand, contribute to the best preservation of paintings; scientific methods make it possible to measure and analyze the influence of external factors - light and climate on their safety. The degree of illumination greatly affects the properties of the painting. The museum laboratory has measuring instruments that allow you to select the lighting that best meets the requirements for the preservation of paintings. Some government (AFNOR) or international (1СОМ) organizations disseminate scientific developments in this area.
But most of all, museum curators insist on a climate and humidity favorable for paintings. Research to date has proven the key role of humidity. Sudden changes in temperature lead to changes in humidity and are considered destructive. Central heating, which dries out moisture, is also a negative factor for painting. The study of air pollution and its impact on the preservation of paintings is also the subject of research in France and other countries. But museum laboratories must engage in scientific research on the paintings themselves. Using the methods listed above, you can detect damage to the base, swelling of the paint layer, and the interaction of pigments and binders. After laboratory testing to accurately determine the size of the damage, restoration can be carried out.
Expertise
The expert, like a doctor, supplements the visual examination of the picture with information obtained from scientific research. Thanks to microscopes, you can recognize fake craquelure and distinguish old pigments from modern ones. X-rays and infrared rays reveal the invisible state of a work of art, which the copyist or forger could neither comprehend nor reproduce.
Dating
Dating of the elements that make up the pictorial material is carried out in several laboratories in the United States, France and Germany. There are four methods for this that are still at the experimental stage. Work recently undertaken by the Mellon Institute in the United States makes it possible to date paintings using carbon 14, which identifies older forgeries (less than a hundred years old). Indeed, since the beginning of the 20th century. The percentage of carbon 14 in the biosphere has changed, and its concentration has doubled from 1900 to the present day. The difference between modern oil and ancient oil can also be established on relatively small test samples (30 mg) using miniature counters. Lead white is one of the most commonly used pigments. Measuring the isotopic ratio of the lead contained in the pigment can be very accurate and can help answer the question of where and when the painting was executed.
Two other dating methods are still in the experimental realm; they are based on the activation by neutrons of foreign impurities contained in lead white and on the natural radioactivity of lead. But scientific methods are especially important for a deeper knowledge of painting itself. Physical and optical techniques reveal the stages of the creative process and recreate the characteristic features of the artist's technique: rubbing of paints, soil analysis, brush width, position of light - all this is very important for the art historian. Science is called upon to improve traditional methods of historical study and preservation of works of art.
We are starting a series of publications in which we will talk about the methods used in researching works of art. The first method that will be discussed is one of the oldest and most widely used in the study of painting. This is an X-ray examination.
A little history
X-ray photography was discovered by the German scientist Wilhelm Conrad Roentgen in 1895, and a year later the first X-ray photograph was taken in Russia. The method is based on the fact that X-rays (in the spectrum of electromagnetic waves they occupy a place between ultraviolet and gamma radiation) have a high penetrating ability. On the film they leave a shadow image of the structure of the object being studied.
The method was developed for medical research, but quickly found application in the study of art. Already in 1919, the tireless Igor Emmanuilovich Grabar initiated the development of a methodology for studying works of art using R rays. Initially, this was done by the Moscow Institute of Historical and Artistic Research and Museum Studies (one of the first institutions coordinating the museum work of the young Soviet state). And in 1925, the country's first laboratory for physical and chemical research of art monuments was opened.
Today in Russia the method is widely used in forensic examination, but it works best if the photograph can be compared with photographs of reference works of painting by a particular artist. Therefore, large museums and research centers (including ours) are constantly adding to their collections of such images - X-ray libraries (they store tens of thousands of images).
How are x-rays done?
For research, special X-ray machines are used, and very often, in the absence of devices designed specifically for studying works of art, laboratories in museums and restoration workshops are equipped with medical diagnostic devices or devices for industrial control.As in medical research, for X-raying works of art, laboratories are equipped with protection from high voltage and X-rays.
The painting is placed horizontally, X-ray film is placed under it and the radiation is directed. The rays pass through the painting and create a shadow image on the film. In special cases, specialists can try out various types of research, for example, microradiography (to obtain enlarged images), as well as angular and stereoradiography (to obtain information about the three-dimensional structure of an object).
This is what the first X-ray machine looked like.
What does an x-ray do?1. Understand the principles of constructing a paint layer, the characteristics of the soil, the method of applying a stroke, modeling forms and other author’s techniques that are individual to each artist
For example, these:
3. Detect the underlying paint layer, if there is one.
For example, under Marevna’s still life the inscription “Peace-Labor-May” and a flying dove were found.
4. Determine the degree of restoration (if any), destroyed areas, losses, as well as transfer of the work to another basis (if restoration is required).
