First of all, conduct a detailed inspection of the work before restoration. The inspection process can be divided into four aspects:
1. Research on the work
Understand the author and At the time of creation, look for relevant information and painting characteristics about the painter, such as the painter’s usual materials, colors, brushstrokes, creative style, creative concepts and aesthetic views, etc. This kind of investigation can allow the restorer to establish a deeper understanding of the work. Only during restoration can we more accurately grasp the original creative appearance of the work.
Second, status comments
First of all, it is necessary to determine whether the painting technique is oil painting or glue painting, and record the size of the work. Size, theme, artist's signature, completion date, storage status of inner and outer frames, etc., record these basic conditions before conducting in-depth analysis.
A, substrate: identify the substrate used The material is linen, jute, hemp, cotton, mixed fiber, wood or fiberboard: the fixing method is nailing or nailing with a nail gun; the storage condition is free of damage, oxidation corrosion, moisture mildew, microorganisms or insects, etc. Phenomenon; whether it has been repaired by predecessors, the repair method and the adhesive used.
B, "priming" of the substrate: Understand the color of the "priming" of the substrate, the substrate has There is no separation, floating, cracking, peeling or microbial damage.
C, painting layer: analyze the adhesive used in the paint; the thickness or thinness of the painted layer; the color tone is bright, Gray or dark tone: whether the color technique used is transparent painting or opaque painting: the brush strokes are delicate or rough; whether the painting layer is cracked, whether it is partial or comprehensive, how deep the crack is, whether peeling has begun to occur; whether the surface of the color layer is cracked Blisters appear, etc. Comment and analyze the extent of these factors.
D. Protective layer: First identify whether there is a protective layer, whether it is full or partial, the number of times it is applied, and the thickness. Carefully identify the transparent color< /p>
Whether there is any disease, damage or microbial invasion related to the color of the Vannis layer.
3. Laboratory diagnosis
A Ultraviolet irradiation: Ultraviolet irradiation can be seen through Inside the protective layer and the painting layer, when this ultraviolet light shines on the surface of the work, it will show blue-purple refracted light. Using this refracted light, the chemical reaction of the painting layer and the disease status of the protective layer can be judged.
B, infrared: Its radiation principle is the same as that of X-rays, but its radiation function is not as strong as X-rays. However, its perspective range far exceeds that of ultraviolet rays, and can reach the coating layer and sketch layer of the substrate. Therefore, it can provide the restorer with quite accurate information.
Four, take photos and archive them
The art work will feel completely different before and after the restoration. Therefore, be sure to take photos before restoration. It is necessary to take photos first and archive them as witnesses for future comparisons. In addition, during the restoration process, photos of the original appearance of the work are often needed as an aid to grasp the color, composition and other key points of the entire work. The focus of taking photos includes the complete integrity of the work. , the back, inner and outer frames, and then use a macro lens to take partial close-up photos in a segmented manner.
Preparation before backing off the substrate
1. Preparation of the new canvas
Choose high-quality linen cloth with fine grains and uniformity, and stretch the canvas on a frame that is 10-20 cm larger on each side than the original canvas. When stretching the cloth, be sure to keep straight lines with equal distances, so that the canvas is stretched. It will not cause an imbalance of strength. Then spray the canvas with water. After the canvas is dry, rub it with your hands on the canvas and tighten the canvas. Repeat this three to four times so that there will be no incompatibility between the old and new canvases. , and increase adhesion.
2. Preparation of old paintings
A. Dismantling and cleaning of inner and outer frames: Do not use arbitrary force when dismantling inner and outer frames, and must use considerable force when dismantling them. Be careful not to damage the painting layer and substrate. Use a vacuum cleaner to gently clean the dust on the surface, or use a brush with very fine bristles. Be gentle and careful when doing this.
B. Flatten the canvas: Use acid-free kraft paper to paste the painting on the wooden frame. To avoid peeling off during the flattening process, the picture needs to be covered with cotton gauze paper, and then covered with cotton gauze paper. The gauze paper is then surrounded by kraft paper. The mounted old cloth will be naturally tightened and flattened by the tension on the four sides during the drying process.
C, clean the back of the old painting: when it is old After the painting is mounted on cotton gauze paper, you can turn the work over to the back and clean the back. Generally, old works are kept for a long time, and there will be
A lot of dust, bacteria, and insect eggs are attached to the surface of the back, which must be cleaned thoroughly, otherwise it will affect the adhesion effect after transplantation.
3. Preparation for wax
New and old canvases and peeling paint The adhesion between them depends entirely on the prepared wax liquid. The wax formula is: pure beeswax: dammar resin: turpentine. Beeswax itself is sticky, and dammar resin is also a good adhesive. Turpentine can soften beeswax and dammar resin. .The preparation method is to heat and dissolve a certain proportion of beeswax and dammar resin, add turpentine, mix and cool, wait until it is completely solidified, then heat it again to completely dissolve it, and then it can be used.
Wax support for new and old canvases Closure
When all the steps are ready, you can start gluing the old and new canvases. First, turn the flattened old canvas face up, seal it with glue and cotton paper on the stretched new canvas and wait for it to dry. , then melt the wax, and then apply the wax on the back of the linen canvas with a brush. After applying, heat the wax with an iron to make the wax penetrate the new canvas and reach the old canvas. At this time, special attention should be paid to the heating temperature and pressure. After ironing, lay cellophane paper on the wax surface, cool it with iron sand, and remove excess wax. Then press it with iron sand for one to two days. After hot ironing, cooling, and flattening, the old and new canvases will be tightly combined, and the paint will peel off. There will be a layer of wax base. At this time, wet the cotton sandpaper on the front and tear it off. If it is difficult to remove, you can wipe it off with petroleum ether. The old painting will be completely exposed. Cleaning and repairing the surface of the work is the most dangerous and difficult task, because it is Once this work fails, it will directly affect the original appearance of the work. Especially cleaning the screen, if the cleaning is excessive, the work will not be able to restore its original appearance.
1. Cleaning the screen
When preparing cleaning solvent , first of all, you must distinguish the strength of the solvent. There are many solvents that will seriously damage the materials used in the work after use. Sometimes they will even corrode the bottom layer of the work and make the texture of the bottom layer soft, such as acetic acid, ammonia, butyric acid amine, etc. It should not be used. Commonly used solvents include: white spirit for painting, pure turpentine, alcohol, acetone, benzene, xylene, etc. There are many solvents that can be mixed into two, three or even four types for use together, and each solvent All have their own characteristics and dissolving functions, which completely depend on the degree of material contamination and tolerance of the work. But no matter what method is used, the most basic thing is that the restorer must first test the cleaning function of the solvent on a corner of the work. , can only be used after making sure there are no problems, so as not to cause regrettable damage to the work. The cleaning process is to dip the prepared solvent with cotton and apply it on the surface of the work and rub it gently. Gradually, you can find that the cotton is infected with Vannis. If the layer or dust turns dark yellow, usually until the cotton is no longer stained with any stains, it can be roughly determined that it is clean. At the same time, the paint must not be damaged. The success of the cleaning work depends entirely on the personal experience and judgment of the restoration.
Second, fill in the white paste
If the surface of the work is cracked, peeled off or damaged too severely, resulting in many sunken blank spaces, it is necessary to fill it with white paste to restore it to a smooth surface. The surface layer. The materials used are to first take an appropriate amount of water-based animal glue, heat it with water heating, gradually add a little honey, phenol and slaked lime, apply the heated white paste to the hollow space and shape the brushstrokes corresponding to the surrounding areas. The place where the white paste has been filled will appear white.
3. Complementary colors
The work of complementary colors has caused controversy among many artists and academicians, because the complementary colors are undoubtedly the work of restorers, so some people Some people think that this will destroy the aesthetic value of the original painting. On the contrary, some people think that this can be called the habit of repairing the damage to the work. When deciding to make up the color, you must first analyze the color layer to ensure the restoration effect, and use the complementary color. The material should be high-quality watercolor. This kind of watercolor is convenient and risk-free to use because it can be washed with water at any time. After the base color is dry, apply Vanis (protective varnish) and then apply special oil paint for repair. This oil paint can be easily Use turpentine to remove it. In principle, the complementary color should be one degree lighter than the surrounding color for easy identification in the future. All the added colors can be easily removed in the future. After the above series of work, a worn-out work has been basically repaired. As for the framing and other work, it can be It depends on the content of the work and personal hobbies. Preserving the oil painting for a long time should be the main task of the collector. It is necessary to find out the cause of damage and eliminate it, so as to ensure that the life of a work is extended to the maximum extent. Major museums and art galleries in China are very important in oil painting. There is almost nothing in the field of restoration, but oil A restoration involves many fields and deserves in-depth study. This article provides a general introduction to the restoration of oil paintings, aiming to attract the attention of the cultural and museum circles. The restoration and protection of Chinese oil paintings is something that the cultural and museum circles should pay attention to. It should also be borne. Restoration workers
The specific work of restoration workers includes inspection, recording, implementation of restoration, protection and prevention measures for oil paintings. Restoration workers need to study the production methods and materials of oil paintings; study painting and painting history; study repair methods and repair materials; therefore, they must have certain knowledge of physics and chemistry.
The knowledge, skills and experience of the restoration worker are crucial to the quality of the restoration. A good restorer can restore a frequently destroyed oil painting to almost like new condition. However, this does not mean that he or she can turn an originally bad painting into a good one. The restoration worker’s responsibility is only to maintain and restore the original appearance of the work, nothing more and nothing less.
The quality of the restoration work should not be affected by the restorer's personal aesthetics. Restorers should not make arbitrary changes to the restored paintings according to their own preferences or the requirements of the painting owner. The quality of the restoration work should also not be compromised by financial considerations. Any work of art is part of the history and culture of a certain period, and its value is difficult to determine based on market or cultural fashion. The purpose of restoration is to allow future generations to have the opportunity to appreciate it. Restorers should treat every painting they restore equally.
Restoration workers must have a correct understanding of their own abilities and experience, as well as the existing conditions of the studio, and avoid doing things beyond their abilities or that they are not sure about. Restoration studio The restoration studio can be around 100 to 150 square meters in size and needs to have good light. Basic amenities include air conditioning, exhaust, water and sewer, dedicated electrical circuits and 30 amp plus electric meters. Studio furniture includes several workbenches, metal cabinets for storing chemical products that comply with local and unit fire protection regulations, storage racks for oil paintings and paper rolls, etc. Office supplies include computers and computer workstations, printers, filing cabinets, etc. Others include general art supplies, photographic equipment, laboratory equipment and labor protection supplies. Some specialized equipment, tools and materials need to be imported if they are not currently produced domestically. The most critical piece of equipment is the thermal vacuum workbench. Based on my understanding of the prices of relevant equipment at home and abroad, it would cost about RMB 500,000 to establish a medium-sized oil painting restoration studio in China that meets the standards of modern museums, including the initial training of personnel. 2 full-time restoration personnel. "Old Paintings Renovated" and Old Paintings "Renovated" As time goes by, the colors of many oil paintings gradually turn yellow and darken, and in severe cases, the entire painting becomes dark ocher or black. There are two main reasons for the yellowing and darkening of oil paintings: first, the original varnish cracks, turns yellow and becomes opaque due to aging; second, the accumulation of dust, including soot, nicotine and insect excretion material pollution. Dust and aged varnish cover the surface of the painting like a veil, making it difficult for people to discern the original color of the painting. It changes the tone and color contrast while weakening the clarity of brushstrokes, detail, and the overall painting, resulting in the aged look and "soy sauce tones" often associated with older oil paintings. It is important to point out that this situation is caused by the covering on the surface, not due to a change in the color of the oil paint itself, nor is it an intentional creation by the artist. The process of darkening and yellowing the surface of an oil painting takes time. The degree becomes more obvious as time goes by and will not remain static. The visual effects at each stage are beyond the control and prediction of the artist himself.
The cleaning of oil paintings is to remove dust or aging varnish on the surface, so that the original colors can be seen again and restore their original appearance. It is not about adding new colors. "Renovation" is not an exact term for oil painting restoration, it should be replaced by "cleaning". Cleaning is only one part of the repair process. In many cases, the color of a washed oil painting is so different from that of an unwashed oil painting that a layman has to wonder whether they are the same painting. However, this kind of suspicion is no longer common in countries where oil painting restoration is popular.
Having never seen the true face of the original painting, some people advocate retaining the outdated appearance of the old oil painting because it is a trace given by history. They believe that cleaned paintings sometimes look too new and thus lose their due value. There are many people in China who hold this view, including many people from the art and museum circles, but there are very few oil painters who hold this view. The limitation of this aesthetic is that it places too much emphasis on the appearance of general oil paintings and ignores the specific performance of specific works. This means replacing the wishes of the creator with the wishes of the viewer. The old appearance can give people a sense of ancient history, but it prevents viewers from visually experiencing the author's creative intentions and artistic style at that time.
Take the works of European Impressionist painters as an example. If they are not properly maintained and cleaned, they will be covered by a layer of "soy sauce tone" after decades or centuries. Perhaps by then, there will still be people who are content to appreciate their obsolescence, but they can only understand the Impressionist colors from books, but cannot truly recognize and feel them visually. They have never seen the original appearance of these works, so it is impossible for them to fully and correctly understand this period of history. By the same token, our understanding of the art of some early Chinese oil painting masters is limited because many of their works gradually lost their original appearance due to aging and damage over a long period of time. Modern people's understanding of them is based on their current condition and appearance, which is quite far from their original appearance. Over time, once the original appearance of the work is restored, people must re-evaluate the works of the early oil painting masters and re-understand their art, which requires the use of other standards besides "obsolescence". Some people are uncomfortable with this because they can no longer measure its value solely on the basis of obsolescence.
Fundamentally speaking, the purpose of restoring an oil painting is to preserve an oil painting in its original appearance so that future generations can have the opportunity to directly appreciate it. This is different from protecting other antique cultural relics. As a visual art, oil painting has its own special artistic language and appeal. This appeal is conveyed visually. Preserving and restoring the visual appearance of a work as it was completed is a matter of respect for the art, respect for the specific work of the specific painter, and respect for history.
During the restoration process, certain traces of history can be preserved, provided that they no longer cause further damage and that the fundamental appearance of the original work is not affected by them. Dust and dirt on the surface of the painting must be removed because they will further contaminate and erode the varnish and pigment layers of the oil painting. Removing or retaining the original varnish depends on the situation, such as whether there is still considerable transparency, whether there is moisture and whitening, whether there are cracks and peeling, the degree of discoloration, solubility, and operational safety, etc. The advantage of retaining the original varnish is to avoid the loss of pigment caused by excessive cleaning. Sometimes the dirt and varnish are actually difficult to separate, or the varnish is on top of the dirt, or the two are covered alternately. In this case, a thorough cleaning is the only feasible solution. There are few successful examples of partial and selective cleaning. It often causes changes in the relationship between colors in the painting. At the same time, the remaining varnish will further deteriorate and discolor, destroying the original visual integrity of the painting. Restorers must conduct careful testing and analysis before cleaning. The range of complementary colors should be strictly controlled to avoid covering the unlost parts. In most cases, cracks do not need to be filled. For supports, renovation or reinforcement should be considered first, and replacement should be done as a last resort. The entire restoration work was based on necessity and tried to maintain the original structural form of the work. In this regard, we have some similarities with the theory of "old paintings and old repairs". But for those oil paintings that are too old, it is often impossible to both reproduce the original appearance of the work and preserve the traces of history. Restorers should respect the artist's original intention as a principle and communicate well with collectors and art historians when dealing with specific oil paintings.
With the popularization and development of oil painting restoration and oil painting maintenance knowledge, many preventive and repair work will be carried out before problems occur or the damage is not serious. This is to save an oil painting in the best possible way. The most ideal way to preserve it in its complete form.