Cypress Tree in the Wheat Field, 1889, painting by Van Gogh, oil on canvas, collection of the National Gallery of England
Cypress Trees in a Wheat Field (Details)
The Aging of Works of Art by Paul Taylor by Yang Jing translated by Jiangsu University Press
When you're faced with a fascinating painting, the repainted, patched, contaminated parts of it can blind you, not to mention the elusive discoloration of the pigments. For example, shiqing, a common blue pigment, is widely used on cave temple murals, but it is not stable enough to become malachite, a green pigment. Those who do not know the situation may think that a large area of green is used on the Dunhuang murals, but in fact, the painters at that time may have used blue.
If you're lucky enough to see the Impressionist painting "Streets of Paris on a Rainy Day" from the Art Institute of Chicago, you might think, like most viewers over the years, that the lady in the painting is wearing a pair of pearl stud earrings. However, after the conservators cleaned the aging varnish layer on the surface a few years ago, it was discovered that Kayebot had actually painted a diamond!
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A few days ago, Zhejiang University Press launched the book "The Aging of Works of Art: Scientific Stories Hidden in Art History" written by British art historian Paul Taylor, which revolves around the lives of many works of art. I think that in addition to wanting the reader to understand the artwork itself, the author also wants to let everyone understand the "fragility" of the artwork, in order to further seek appropriate means to make these human treasures continue to live.
As we all know, ancient and modern Chinese and foreign works of art have their peak period. A work of art, from the moment it is created, has vitality. Time wears down its appearance, and dynastic changes change the meaning of its existence. A seemingly unremarkable piece may reflect the characteristics of the times at that time, and may also be interpreted in a new way today. In a sense, the life of a work of art can be long and wonderful because of excellent restorers and a proper preservation environment.
If you walk into the Louvre in Paris at the end of 2019, you will be attracted by the "special exhibition of the 500th anniversary of leonardo da Vinci's death". This exhibition not only gathers a large number of paintings and drawings by the Renaissance master Leonardo da Vinci, but also shows the results of the scientific analysis and restoration of some of the works by researchers. For example, in "Ginevela Banchi" at the exhibition site, the audience does not see the original, but an infrared photographic picture of the same size. Despite being a black-and-white picture, visitors can clearly see the motto "Virtue and Honor" by Venetian diplomat Bernardo Bembo. It is obscured by the portrait of Ginevela in the picture, which is invisible to the naked eye, and the penetrating nature of infrared light makes these hidden details appear in infrared photographs. Equally striking are the Louvre's collection of three paintings by Leonardo da Vinci, all of which have been restored and look even more glamorous.
Perhaps the louvre curators and researchers want the audience to see these masterpieces more authentically, or even change the way they have been known in the past. Without excellent research and restoration work, these realizations might still be in vogue, as the diamond stud earrings of the lady in the famous painting "Streets of Paris on a Rainy Day" have long been regarded as pearl jewelry.
This is exactly what Paul Taylor, an art historian at the Warburg Institute at the University of London, fears — that many precious works of art are undergoing ageing and destruction, obscuring scholars' eyes and allowing them to draw imprecise conclusions in their respective fields of study. In The Aging of works of Art, Taylor cites a large number of real-world examples of how many outstanding paintings do not look exactly what they originally looked today, and criticizes the pursuit of theoretical flaws based on visual evidence, without first trying to understand as much as possible about any preservation in problematic works, because natural aging and artificial tinkering are so common in works of art that any research can go astray without figuring out what the paintings looked like in their original state.
So, what ageing problems may occur with these paintings? What is the reason behind it? The Aging of Works of Art expresses concern about these issues that may be overlooked in the study of art history—what materials are in the paintings? How do they change in collision with time? How did these changes affect the appearance of the work?
In the book, Taylor begins with the painting material and technical terminology, detailing the different degrees of changes that occur due to the influence of various materials that may be used in painting due to factors such as temperature and humidity, ultraviolet light, and carbon dioxide in the air, resulting in shedding, cracks, warping and discoloration of the painting. He argues that the negligible survival rate of artworks may be largely due to preservation conditions — not just common factors (such as war, fire, ideology, etc.). For example, the widely used red pigments lead dan, cinnabar, blue pigments such as stone blue, ultramarine, etc., as well as the varnish layers used in Large Quantities in European Painting, their discoloration and darkening are so common that scientific research on these phenomena in recent years has also reminded us that the preservation problem of how many works of art is shaped by the particularity and complex variables of material, technology, environment and restoration history, and even to summarize their deterioration mechanism is so difficult.
Therefore, when we are faced with a van Gogh or Vermeer painting, if there are small cracks or sesame-sized pigments falling off, the audience may be indifferent, and the artists may not necessarily pay attention, but these cracks or pigments are by no means the "emperor's new clothes", they may continue to grow and develop, and eventually cause great damage to the painting. How to deal with these problems is the professional work of cultural relics conservation scientists and restorers. In the book, Taylor gives different coping options in detail. For example, "cleaning" is a common means of treating the aging varnish layer on the surface of oil painting. After learning the lesson of "over-cleaning" by restorers in the early 20th century, conservators today adopt a relatively cautious approach to cleaning, usually retaining a thin layer of old varnish during the cleaning process to avoid excessive cleaning and careless removal of subtle surface layers. While striving to make these interventions reversible, today's conservators are also paying more attention to the transparency of conservation restoration work, just as the Rijksmuseum shows the public the restoration process of Rembrandt's masterpiece Night Watch, and the Royal Institute of Cultural Heritage of Belgium cleans Van Ike's Ghent Altarpiece in a glass room of the Ghent Museum, so that the viewer can intuitively understand how to deal with an "aging" work of art.
To make the public aware of the "aging" process of works of art, and the value and significance of scientific protection of them, is an important purpose of Paul Taylor's book, which coincides with the original intention of the exhibition protection that professionals in the field of antiquities and museums have been promoting in recent years. In the case of the Rijksmuseum's "Operation Night Watch", scientists used state-of-the-art instruments to scan the paintings on full-scale compositions and found some unexpected details. For example, Rembrandt used an arsenic-containing pigment to paint the embroidery on the lieutenant's clothes in the center of the picture. In those days, these pigments were mainly used to paint flowers and fruits in still life paintings, while Rembrandt used them in the costumes of figures, which was considered an innovation. A feather originally painted with iron-containing paint was also found on a soldier's helmet, but Rembrandt somehow ended up smearing the feathers. For a long time, the research and protection of precious cultural relics and works of art have been carried out in laboratories or warehouses, and the "Night Watch" action has placed this work directly in the exhibition hall and become part of the exhibition, unveiling the mystery of cultural relics research and protection, and the audience can even interact with scientists and restorers on the spot. In addition, such large-scale research, analysis and restoration, and the acquisition of a large number of new discoveries, can provide more valuable materials for the future display of "Night Watch". This kind of scientific discovery and technical application in the process of research and conservation restoration, and the display of artworks centered on this, fully reflects the perfect combination of science and art, and the important role of contemporary scientific and technological progress in promoting art history research. This is also an important point that Taylor wants to express.
It is worth noting that although paul Taylor lists most of the oil paintings from the National Gallery of Art, he also occasionally mentions the preservation of Chinese paintings and Japanese ukiyo-e. This is due on the one hand to his curiosity about non-European art, and partly because research reports on the "aging" of Eastern paintings are rare in the West. This does not mean that a Song Dynasty painting will not have cracks and pigment discoloration, but the relevant research is not sufficient. Although there are obvious differences between ancient Chinese paintings and European oil paintings in terms of materials and structure, the problem of "aging" also exists, and the traces of past restorations may also obscure important information about the original work, and even what kind of pigments are used in the picture may not be clear. For example, the color "rouge" is a very common color in ancient Chinese painting. However, what pigment was it drawn from? Professional painters or painting enthusiasts know that pigments that can show the color of "rouge" may have mineral pigments such as cinnabar, and lac worms and cochineal insects derived from insects, as well as dyes such as sumu, madder, and safflower from plants, can also show this color. In fact, all kinds of paper may also age under certain conditions and have an impact on the preservation of calligraphy and painting works. Solving these problems requires the intervention of scientific and technological means and the close cooperation between scientists and artists.
A work of art, or artifact in the broader sense, becomes part of nature from the moment it is created. Therefore, its aging is also a natural phenomenon. The study of it can expand human understanding of the world. At the same time, it is also to find the appropriate means to make it continue to be preserved. Thus, the study of "heritage science" has both a clear application goal of extending their lifespan and, as Professor Matthia Strelitch of the University of London has pointed out: "The science of heritage enables society and individuals, as well as our future generations, to practice their rights to cultural heritage and to contribute to the understanding of our own humanity and the world in which we live." It has a deep social purpose. ”
(Author: Zhang Hui, Associate Professor, School of Art and Archaeology, Zhejiang University)
Source: Guangming Daily