الحفر أو الطباعة ٢ _ a , من كتاب تكنولوجيا التصوير , د.م محمد حماد

From this we see that this method of printing is for drawing (Fig. (46)... As for the shades of color and its average value, it can be recorded by dotting or dashing (Fig. 47) parallel or intersecting. In the printing process, strong pressure is required.. Also, the letters of the tablet leave a mark Or notch known as the influence line of the board, and it is not devoid of beauty as it gives a definition to the drawing.The value of the painting always depends on the integrity of its lines and accuracy next to its artistic composition.This type of engraving has been famous among English artists since the beginning of the nineteenth century and has become the arts that It is taught in both technical and industrial colleges and schools

Acid etching

This process is similar to the process of etching in the method of making lines to define the drawing, but the lines that are usually on copper or zinc plates are etched here with acid that works to corrode them instead of etching them by hand using a corkscrew (Fig. The acid affects it, so it does not run out of it to the metal. As for the lines that are drawn, they are bare of varnish or wax, and they are corroded and etched if they are exposed to dilute nitric acid. The depth of the lines is determined by the period of their exposure to the acid, and the lines that are feared of corrosion should not be exposed for a long time to the acid and immediately covered with varnish.

(Fig. (48) A drawing copied from the antiquities and printed using the acid-etched zinc method.
Rembrandt Whistler This method of acid etching was developed by the two great artists Rembrandt and Anthony Van Dyek in the seventeenth century, and acid etching became widespread since then, and it was used by many artists in England and America such as Whistler in the nineteenth century. And the beauty of this type of engraving appears in the freedom of lines and the different artistic effects that can be obtained. This type of drilling may be used in conjunction with aquatinta drilling or direct drilling on metal with the drypoint needle

E - Soft ground etching

This is another type of engraving, but it is less used than the previous one, and the effect of its drawings appears as the effect of drawing with a pencil or a soft charcoal pencil, and for that reason it is called engraving with pens.... except that the English call it soft-ground because it works using varnish or soft ground (and this varnish It is composed of 2 volumes of mastic, 2 volumes of asphalt powder, 2 volumes of beeswax, and 3 volumes of cowhide. Then paper is placed on the surface and drawn on it with a pencil. Here we find that the pressure of the pencil causes the soft varnish to transfer to the surface of the paper, leaving lines similar to the original lines drawn with a pencil. After that, it can be treated with nitric acid to etch it and use it in printing as usual. father-in-law

6- Engraving to make Aqnatinta color gradations:

This type of etching is also acid etching, as its lines are etched with acid on the metal plate, but this type of etching relies on showing the color tones in the spaces (Fig. 49) instead of showing them with lines or dots. The method of its implementation is as follows:

The surface of the board to be drawn on is covered with varnish, like the previously explained engraving with pens, then the drawing to be engraved is transferred to it with carbon, then engraved with a needle or an engraver.. Then it is then exposed to acid for the period required for engraving. Then the surface of the board is cleaned from traces of varnish with turpentine or benzene, and it is cleaned again with soap or soda. After the surface dries, it is dusted with soft, well-drained rosin resin, using a special pillow, and then subjected to a quiet fire in order for the rosin atoms to stick to the surface, then The parts to be left white are covered with liquid varnish, and the board is then exposed to acids for a very short period (no more than seconds), and this process is repeated successively according to the color to be made. It is noted that the parts that are exposed for a longer period of time in the acid increase their shade and become darker.
Figure (49) A drawing showing the shape of the work of color spaces.

After completing this process, the surface is cleaned and can be printed under pressure

As usual

7- Mizzotinte engraving:

This method of engraving was discovered at the end of the eighteenth century, but it did not meet with remarkable success, as it did not rely on artistic creation and was limited mostly to transferring the boards of famous artists.. Its method is as follows:

A cutting machine with a sharp knife (named Rocky) is passed on the surface of the board to be worked on, and it is passed lengthwise and widthwise so that this process produces equal holes that this machine leaves its mark on the surface in a regular manner. The process of obtaining white spaces.. The more pressure this machine has on the surface with the holes specified by the rocky, we get spaces to the degree of openness. This process continues until the burnisher completes the work.
in the required technical manner. Then the printing process is carried out as usual under the pressure of the printing machine. This method gives a result close to students' clichés

currently used.

Stipple engraving:

This method of engraving is often used with the method of slashing to show shading or half-color. And it depends on piercing the varnish layer with multiple points, then additional points are added directly on the zinc plate by means of a point borer

stipple engraver

9- Drypoint needle drilling:

It is a self-contained method of drilling, and it also adds an intent effect to the method of direct drilling on the zinc plate by means of a drill with a sharp tooth known as a drilling needle. And that the thickness and depth of the lines depends on the degree of pressure of the artist on the board with the engraver during the engraving. And you notice that the protruding letters on both sides of the engraved lines must be left and not cleaned because they give a rich effect when printing, even if this protrusion disappears after printing a certain number of copies. Therefore, the editions produced in this way are limited. In some cases, the surface of the panels to be engraved is covered with a thin layer of steel, so that the surface is more durable.

10- Lithography

This type of printing was discovered by Aloys Senefelder at the end of the eighteenth century. Most copies of the original manuscripts were produced in this manner, as it gives the artist complete freedom and frankness in transferring the drawings.

The imprinting of the stone has part of the chemical action, as it depends on the main principle that the fatty substance and water do not mix. The drawing is carried out on a special type of stone with an exhaled pen that contains a greasy substance or greasy news. Here, the artist draws as if he were drawing completely on paper, and after completing the drawing, he covers the board with Arabic gum, and we find that both the ink and the glue affect the areas it covers and give it characteristics. Chemically, the part covered with ink acquires the characteristic of accepting fatty substances and rejecting water... And vice versa in the parts covered with glue. By using wax and tartaric acid, we find that the fatty substance rushes into the stone and is fixed. This part on which the greasy substance is fixed usually attracts the printing fluid that is connected to it through the inking roller..while all other parts of the stone surface accept water. In fact, it resembles drawing with news, and it is called dyeing with ink, and obedience to stone can be executed on aluminum and zinc panels. It may also be drawn on special paper with a pen or greasy news, and then this greasy drawing can be transferred from the paper to the surface of the stone under extreme pressure, but most artists prefer direct drawing on the stone and then it is printed by pressure using a special press.

Lithographic printing was widely used in the nineteenth century, especially for female photographers, and this type of printing has many modern uses, and it is a beautiful medium for printing many beautiful drawings of contemporary artists... due to the possibilities it gives, direct directions and flexibility, which facilitates the artist to prove His personality and special character in his work, which can give great richness to the work of art. Among the most famous artists who practiced it were Toulouse-Lautrec, Domier, Picasso and Braque.

Among the artists who adhere to the implementation of their drawings on the stone, and they have a distinct direction in the method of implementation as a result of understanding and benefiting from the basic method of carving the stone, the artist «Viera Gergilo Fa... She cares about roughing the surface of the stone before using it so that the image gains a rich texture, and she also uses Syrian asphalt after melting it in The turpentine becomes in the form of a paste to cover the surface of the stone with a light layer by means of a leather cylinder... The stone is left for two days to dry the thin asphalt layer, after which it can be drilled with a fine needle. Then it is treated with gum arabic and diluted nitric acid to be ready for printing. And you see in the form of (50) engravings from the artist’s work, “Veira Gargilova, which represents engravings from an idea

For the poet Pushkin, three colors were used in it: black, blue, and red. In this way, it is possible to print in several colors, provided that a stone is prepared for each of the required colors. In addition, it is not correct to print any color except after the color printed before it has completely dried, so that the colors do not mix with each other. some.

11- Transfer or offset printing:

It is the modern development of lithographic printing, and it relies on its basis, like it, on the idea of ​​the contrast between oil and water... although it differs from lithographic printing in several respects.

The most important of them:

(a) The material used changed from stone to thin sheets of zinc metal or

Aluminium .

(b) These panels used, with their flexibility, enabled them to be installed on a rotating cylinder, which helped in printing speed.

(c) The printing in this method is not directly on the surface of the paper, but rather it is transferred from the printing surface cylinder to another cylinder covered with rubber, which transfers the printed form (drawing and writing) to the paper to be printed on... Hence this method is called transfer printing. We note that the drawing here is on the printed surface in its natural position, and that reflects the stone on which the shape is drawn in reverse.

12- Silk screen printing:

This type of printing was first used on a commercial basis