صيانة التصوير واختباره ١_a , من كتاب تكنولوجيا التصوير , د.م محمد حماد

- Maintaining and testing imaging

After the photographer finishes his work, these works of art are exposed to all the chemical effects arising from the use of the materials used in photography 100 and the photographed paintings must bear all the weather factors that they will be exposed to ... They are also exposed to worms and some insects such as the biting insect, which affects the wood that may Draw pictures on it.

It is necessary to know the initial precautions that must be taken to ensure the safety of the painting... Therefore, we must have knowledge that helps us to take successful treatment methods that can be followed in the event of injury. Since, during these procedures, accurate analyzes must be made of the building material of the artwork itself... We refer here to the importance of practical tests and the traditional methods in force to verify the integrity of the work. Therefore, we will mention here a word on the rules of conservation and maintenance followed by the major national museums and restoration institutes in the world

Photographic maintenance:

It is understood from the meaning of maintenance that it is the care that must be surrounded by the work of art so that it retains its original splendor over time ... Hence we see the importance of protecting it by means that prevent or remove all kinds of materials and impurities that may be attached to it or affect it, even if that sometimes leads to something Change in relation to the work, such as removing the varnish or re-painting it.

In many cases, the matter is related to the restoration of the paintings... any operations in which personal technical intervention is required 000 because it is the same construction of the work, whether it is restoring the canvas of the painting or cleaning the usual photography... etc. We can explain the maintenance conditions as follows:

1- Natural events...

It usually results from the use of the same materials

Support or carrier, pigments and medium

(1) Cloth as a support material for photography is affected by the extreme tension or pulling that occurs as a result of the extreme heat of the atmosphere... and it may lead to tearing, and this results in
. Also, on the increase in humidity in the air, which follows the intensity of the heat, and we often find that the very thin cracks in the pictorial linings of old paintings were caused by this source. One must also beware of changes in air humidity in the halls provided with central heating (which usually tends to dry the air) when the heating is left to cool the halls. Here, severe deviations in the degree of humidity are noted, and it must always be kept between 11% and 55%. However, it is better, of course, to keep the temperature and humidity constant during the night or day at one degree, if possible. It also notes that lighting gas and coal heating pose the same dangers to photographic work. Therefore, we find that all types of canvas can be affected by these factors and oxidize quickly... And we can resort to a way to protect it, of course, by covering the canvas from the back with a light layer of glue or kaolin, and by using insulating sheets or foil of zinc, aluminum, or Paper .. In many cases it is desirable to renew the cloth, and in this case the old cloth is pasted from the back onto a new cloth prepared to bear the tension on the frame. Sometimes the decomposition and tearing of the old cloth is great... In this case, the old cloth can be removed and a new cloth can be put in its place. The process begins by sticking a sheet of paper on the face of the picture, then gluing a regular cloth over it to fix the colors of the face... Here we can remove the old cloth from behind The plate and stick the new canvas, then remove the gauze and paper previously attached to the front of the plate. We note that this process is very accurate and depends mainly on the skill of the restorer. This same process can be carried out in the pictures drawn on wooden boards, then they are transferred back onto the wood material or onto the canvas if the matter requires that.

(b) Wooden props.. Wood as a support material for photography is subject to the same dangers in another way. The wood bends, expands, and shrinks according to weather changes... Hence, straight-line cracks are created in the paint colors of the picture. Advertising is often the cause of these incidents. Accordingly, a network of wooden struts shall be fixed on the back of the board and the frame to strengthen the length and width in order to resist bending. If the resistance of the wood is strong, then the various factors cannot affect it... What is important first is to choose wood with organized fibers, then to coat it with a substance such as copal over and behind the beams of wood.

In the case of old paintings, the problem of worms, insects and mold from mushrooms can be treated by fumigation. But if corruption or decomposition has already spread to its fibers, it must be sterilized first, then remove the infected wood with a mouse and chisel, then transfer the image to a new support.

(C) pillars and other load-bearing materials such as walls, which are sometimes damaged. Unevenly distributed moisture, temperature fluctuations, parasites and salts separating the paint from the surface of the wall, the different degrees of flexibility of the types of primers, the inappropriate amount of the constituent elements... All of these factors have an effect on the bearing surfaces and the images painted on them, and the treatment method differs from one case to another. To resist moisture in the walls, an insulating material separates
Caséate de chaux The part drawn from the wet part, or injections are used with calcium cups or alabaster powder, or separated with moisture-proof sheets such as lead chips, or the drawings are placed on secondary walls isolated in front of the original wall, or fixed in a frame separate from the surface of the wall, or the image is transferred Sometimes in a special way.

(D) Color paint 000 and its deterioration is usually as a result of deterioration of the support or carrier medium or its special composition, so there are sometimes regular retinal cracks such as faience cracks or old Chinese cracks that look like a spider’s web, due to the excessive thickness or thinness of the paint layer..

The answer depends on the type of addiction, whether it is watery or oily... It also depends on its chemical composition, its effect on humidity and atmosphere, and its response to oxidation. Processing it in this case is similar to processing the color layer on the image.

(E) The crust of the picture... The artist is often responsible for its bad condition... as a result of color defects or uneven mixing. Misuse of dough with unstable colors... and other reasons. Some of these defects may be treated by using an adhesive such as wax emulsion in Venice turpentine oil mixed with gelatin and injected in different ways.

(f) Varnishes 000 and it is known that they are the opposite of painting in some way... as they may preserve and fix it... but they usually put a cover on it that changes the shades of its original color. The degree of dilution of oils and resins in a rapidly evaporating or volatile solution.

The bad condition of the varnish is often the result of its use. The blueness phenomenon on its surface (resulting from mold) is the result of painting it at a time when the atmosphere is humid or due to the presence of certain gases in the atmosphere. The traditional treatment that artists follow in this case is polishing with wool, silk, or cotton that drinks water. When this phenomenon reappears, it can be Rub the varnish with a piece of suede or chamois leather, moistened with 20% vegetable turpentine, mastic and 2% castor oil.

Often, cracks appear on the surface of the varnish on old paintings, which precede decomposition, which may reach the degree of powder. In order to treat this condition, the surface of the varnish can be renewed with alcohol, or by re-painting the varnish if the damage has occurred to a large degree.

In the first case, the painting is placed in a box on top of which is wet felt with alcohol. This method is better than the method of removing the varnish, so that some parts of the colors attached to the varnish are still there.