Engraving
In its widest sense, the term is referred to every method of reproduction or reprint of a work in many issues, and thus the block print, lithography, Serigraphy, etc. Literally, however, prints can only be described the products of those techniques where: a) a metal plate is used, usually from copper, b) the ink is "restrained" in carved or created nicks or cracks with the help of an acid and c) the plate is placed in some kind of printing press, so that with the pressure exercised, the paper absorbs the ink from the engraved signs. With both the wider and the narrower sense, the engraving can be either a purely original, independent composition or reproduction of other mean of a certain painting, sculpture, drawing, etc. The main difference between the individual etching techniques usually lies in the way in which the drawing is reflected in the draft plate. In this sense, prints are usually categorized to:
A) Line engraving. The engraver works directly onto the copper, chasing with his tool (chisel) the lines he wants to reproduce. It is the oldest method and requires a great accuracy and tremendous discipline of the hand. The famous engravings of Dürer are perhaps the most remarkable and best known examples of this technique.
B) Dry point or Punta Seca (pointe seche). This is perhaps the simplest method, since the artist "plans" substantially over the plate with a pencil from hard steel. But while in the linear etching the resulted shavings are thrown, here remain in place in order to enrich the line and give a characteristic "glow". This technique, with which only a limited number of copies can be produced, is often used in combination with other etching techniques.
C) Etching (etching, eau forte). The plate is covered with a thin layer of acid-resistant varnish, is carved freely by the artist with a steel "needle" and, after its back and sides being protected with one also resistant varnish, is immersed in a basin containing dissolved acid (usually nitrate). The gradations are much more subtle in this case than in linear engraving and this is because the engraver can cover during the successive immersions in the acid the points that he wants to be attribute smoother with the same acid-resistant varnish, used on the back of the plate. Under the influence of acid, the points which are punctured with the needle are "corroded" and the plate, after being washed with clear water, removed the varnish and inked is ready to be printed. This technique was used in the early 16th century and its potential was fully exploited by artists such as G. Calo and Rembrandt. The so-called soft background etching, the artist designs in pencil on a layer of fat mixed with varnish, but intermediate and placing a sheet of paper between. As a part of varnish sticks on the paper, the final resulting image often has a texture reminiscent of grain or wood grain.
D) Mezzotinta (mezzotinta, mesotonia). Unlike all previous methods, is based on gradations rather than in line. Its use for the paintings’ reproduction was widespread in 17th and 18th century mainly. The plate is etched with a special, relatively large, curved, "cog" steel tool, which allows the creation of innumerable small jags, and then printed as a single, solid black. With more or less radical "cleansing" of shavings, a check is obtained in the amount of ink absorbed by different parts of the plate and therefore the necessary tonal gradations. Today, this technique is rarely used.
E) Aquatinta (aquatinta, watery tone). Method which use acid as in etching and tries to give to the print an engraving project. Devised in 18th century and its ability to achieve an impressive degree of transparency is its main feature. The plate is covered by a porous substance that penetrates the acid, and a procedure is followed similar to that of etching. The famous series of Goya’s prints “whims and misfortunes of war” are the undisputed masterpieces of the genre. In the so-called aquatint with sugar, the drawing is captured in bronze using black ink or gouache diluted in sugar water (this method was used by Picasso for his illustrations of Byffon’s Natural History).