التصوير الزيتي ٥_a , من كتاب تكنولوجيا التصوير , د.م محمد حماد

The other half is on the cloth until you make sure that it is securely fastened... As for the short nails with wide Russians (such as those used by the upholsterer), it must be avoided, because it is easy to damage the cloth if it is necessary to extract them at any time.

And before stretching the cloth on the frame, the wooden keys on the sides of the frame at the corners must be removed. After completing these wooden keys in place at the corners, it is possible, of course, to tighten the cloth if it is necessary to tighten it in case it relaxes from the effect of the drawing on it or from the influence of temperature difference in some cases.

And when fixing the fabric with nails over the frame, the fabric threads should be perpendicular and completely regular with the frame supports. It is sufficient at first to install it with some nails from two corners, one horizontal and the other vertical. After that, it can be tightened from the two remaining corners using a pliers or special pliers (Fig. 63). And so, gradually, it can be fixed with other nails to complete the installation without entering into the tightening process once... Also, the glue that is used in preparing the surface of the canvas - if it has not been previously prepared - will work to tighten the panel in a better way

Figure (63) with a ratio or pliers to tighten the fabric on the frame

And the paints of the preparation process can be of the absorbent type. Or non-absorbable, or absorbable to some extent. And we do not recommend the use of highly absorbent fabrics, because the surface on which the colored dyes are prepared - that is, the oil colors, after it has been absorbed by the gesso used in the preparation, works to weaken the cohesion of the color in a tangible way, and thus makes it easy to extract and disintegrate. Also, fabrics with a high degree of absorption do not guarantee that the painted painting will last for a long time, and vice versa for painting with tempera or gouache ... However, there are painters who prefer to use this equipment in the art of painting with oil, because after the absorption of the oil by the gesso, it results in the colors that are given Opaque effect, which is desirable for some tastes. In fact, there are some painters who are interested in making the colors appear darker, even if they are less stable, so they dilute them by adding volatile oils to them in abundant quantities, so that they can obtain that artistic effect, without thinking about what might happen to their drawings in a short period of time.
Therefore, we prefer methods of preparing oilcloth, which are characterized by their low degree of absorption or non-absorption. In this way, rabbit glue or gelatin glue (which is extracted from fish) and Florence or Spain gypsum which is calcium carbonate or slaked lime are used, as well as crude flax oil (unboiled).

2- Preparing the walls for filming:

The preparation of walls, whether of stone or burnt brick, is usually by painting them with plaster... There are several methods that follow and begin with the preparation of the internal whiteness. And it must be dry and free of moisture and salts, then an oily paste consisting of albedo and linseed oil is prepared to level it, and it is applied to the surface of the wall to be photographed on after sanding it, if it was from plaster. Some people prefer to paint the surface and saturate it with linseed oil mixed with turpentine at a ratio of 1:1, but for reasons of saving oil, some paint the surface of the wall with gumlaca solution so that the absorption of the surface of the wall decreases when painted with oil. In this case, after the oil dries, it is coated with putty and sanded well after drying with sandpaper and pumice powder.

After making sure that the surface of the wall is even and even, it is painted with an oil color consisting of linseed oil and turpentine at a ratio of 1: 1, with the addition of an appropriate amount of zinc oxide and any color to break the sharpness of the white color in accordance with the artist’s taste. After this layer dries, the surface of the wall is prepared to be painted with oil colours.

Surface preparation of wood and similar materials:

Preparing the surface of wood and similar materials does not differ from the previous preparation methods that are used to prepare walls or prepare canvas. However, many painters use the wood surface for painting without preparation, contenting themselves that the nature of the wood surface helps to absorb the oil from which the oil colors are composed.... Also, the wood fibers and the resinous materials they contain help a lot to stick the colors on the surface of the wooden panels. But if the wood is dry, some prefer to coat it on both sides with linseed oil and turpentine in a ratio of 1: 1, in order to prevent weather effects. It is also in some areas that abound. By leveling the wood, these woods can be treated before drawing on them by evaporating them before painting them with oil or saturating them with a protective substance against insects. Some prefer to metal them by leaving them in a solution of liquid glass and water at a ratio of 1:20 for 4 hours, then leaving them in their place and not wet (Mineralisation) for antiques .

These collected wooden panels were commonly used in the past for painting with tempera, and they continued to be used after the spread of many oil paintings on fabrics, especially in drawing icons. And these roofs have been met with ... and even preferred
Drawing on it was accepted by a large number of painters of the eighteenth century, especially in drawing small and medium paintings, but today, artists have replaced it with pressed wood or other types of other compressed materials because it is more secure, durable and saving.

The wooden panels that were widely used by the ancient photographers were poplar wood, beech wood, Turkish walnut, oak, tableau, willow...etc. They also used types of excellent wood such as rosewood, cedar wood and other rare woods.

These wooden panels were chosen so that they did not contain knots (seeds), which distorted their surface and made them unsuitable for drawing. The parts of the wood are joined to each other with a solid, strong glue, such as casein, and strengthened by interlocks of different shapes, as shown in the drawing (Fig. 64). The manufacturer often tried to make it more resistant by fixing pillars in it that differed in the degree of their fixation according to the method of interlocking

Figure (64) Different ways of interlocking the parts of the wooden panel (a) Samara interlock

With a tie between the two boards (b), the interlocking of a lover and a lover, or a male and a female

(c) A tight-fitting coupling for reinforcement.

Preparing the paper surface for painting:

And the paper, by virtue of its manufacture of vegetable fiber materials, seems to be suitable for drawing on top of it with oil. Many of the great photographers drew some of their paintings on paper. Their artistic works challenged the norms of time, and among these works are the works of Giovanni Holbein (1497-1543) and “Paolo Caliari, who was called “Veronese” (1528-1588) and others.