|
| The Technique  First of all, the techniques of artistic reproduction by printing take their name from the material of which the matrix is traditionally made, followed by the suffix –graphy (from the Greek grapho, to write, to draw). In order of historical appearance, we have: XYLOGRAPHY - relief engraving on wooden (from the Greek Ksylon) matrices. SERIGRAPHY - technique that uses a cloth matrix, traditionally silk (from the Latin saeta or seta). CALCOGRAPHY - hollow engraving traditionally on copper (from the Greek khalkòs) matrices. So the name derives from this Greek term, and not, as some think, from the Latin calcare, from calx, calcis, heel, referred to the impression left by the matrix in the printing process. LITOGRAPHY - flat printing traditionally on stone (from the Greek lithos) matrices. The stone is calcium carbonate, this time not from the Latin calx, calcis but from the Greek khaliks, pebble. BURIN This technique, the first to be adopted, takes its name from the tool used: the burin. It is an instrument developed by another artistic discipline, the goldsmith’s craft, a hint on the origin of calcography. This is testified also by Vasari, who credits the Florentine goldsmith Maso Finiguerra with the invention of burin. More likely, instead, burin appeared in Northern Europe, between Germany and the Flanders, always in the middle of the XV century and thanks to a goldsmith, someone able to master an instrument that requires years of apprenticeship. The technique is very simple to explain: usually the matrices are in steel, copper or zinc and the signs are drawn by the burin point. This is the oblique section of a small steel stick that when, pressed and moved on the matrix, cuts a shaving of the metal. The resulting sign is clear and can withstand large editions. Its modulation is due to the shape of the section (square, diamond, oval, triangular, round), to the angle at which it cuts the matrix and to the pression exerted by the operator. It is one of the most difficult techniques, that requires a sure hand that can be obtained through a long apprenticeship. It was the queen of calcography for centuries, especially to illustrate books. Today its autonomous use, not linked to other techniques, is rarer and rarer. The international abbreviation to designate burin is C1 if on steel and C2 on a different metal. DRYPOINT Drypoint too is a direct technique, without mordants. The traditional and most common tool used is a strong steel point, though more sophisticated diamond and sapphire points, which do not have to be periodically sharpened, exist. The point does not remove a shaving but, as a plough, cuts and moves the material: its characteristic is that, just as a plow, produces both a groove and, at its sides, bulges called burrs. With the groove, the burrs too retain the ink and transfer it to the paper in a typical, velvety way. The burrs can be shaved with a scraper to leave only the groove; in this case the sign is similar to the burin’s one, but less clear and deep. The graphic result depends mainly on the angle of the point on the matrix. The hand must be strong and determined, exerting a pression proportional to the hardness of the matrix: copper very hard, zinc softer, plexiglas softer still. The main flaw of drypoint is the low resistance of the matrix to editions: the burrs, being in relief, are easily flattened by the great pressure of the press, and that is why harder materials are preferred. The international abbreviation for this technique is C4. MEZZOTINT Mezzotint is another direct technique, though an indirect variation, when a mordant is used to prepare the plate, exists. In the classical version, the matrix is grained with a strong dented half moon-shaped steel blade called rocker or berceau (from the French for cradle). By rocking this tool and pressing innumerable times its teeth on the matrix, the surface is etched with thick barbs that make the print of an intense and velvety black. The tool is moved on the matrix with a rocking motion and a moderate and constant pressure. A “correct” path exists: first the plate is crossed vertically, then horizontally, then diagonally at 45 degrees from right to left, then diagonally from left to right. The four series make up a round, and to prepare the metal adequately, from 10 to 15 rounds are required. Starting from black, by flattening and scraping the barbs generated by the rocker, passing by lighter and lighter tones the purest white can be obtained. This technique allows very soft and pictorial graphic results, with a great tonal variety. Mezzotint too, a relative of drypoint, has a low resistance to printing, so than copper plates are normally used. The international abbreviation for this technique is C7. ETCHING The more evocative Italian term, acquaforte, derives from the medieval name of nitric acid, aqua fortis, strong water. It is an indirect technique, the most used by engravers, who in fact, in English, are normally called etchers. It is based on the chemical removal of metal from the matrix, using a corrosive liquid called mordant. Historically, the great merit of etching was to free the creativity of artists from the burin and from the need either of a long apprenticeship or of artisans who knew how to use the burin. The plate is first smoothed, cleaned and degreased, then varnished with a special acid-resistant varnish, essentially made of wax and tar. On the surface, after such preparation, the drawing is made with a point that removes the varnish and uncovers the underlying metal, which must be corroded by the acid. Points may have different sizes and shapes to obtain lines of different width, thus widening a little the range of possibilities (flat, truncated, cat’s tongue points); the author, however, draws almost as if were using a pen on a paper. The biting process, the corrosion by the acid, follows. Innumerable “recipes” for mordants exist, depending on the metal used and the tastes and the experience of the etcher. The most common acid is the nitric one, that, in different solutions with water, can act on many metals. The sign is less clear than the one obtained with the burin, but it can withstand large editions. Its modulation, width and depth depend a little on the points used and much on the biting process. The international abbreviation for this technique is C3. AQUATINT It is a relatively recent technique, allegedly invented by the French etcher Jean Baptiste Le Prince in 1768. In aquatint, the sign as expressed in etching, burin and drypoint is bypassed: the images are obtained by filled areas, zones of different tonal intensity, more or less defined or with contours. The principle is the same as the cross-hatching of news-papers and magazines: the ink is mono-tonal and, in order to obtain all shades of the color – normally black, the image is decomposed in miniscule points that the eye does not perceive; the ratio between white and the colored points determines the shade. In this technique, the author creates a sort of hand made cross-hatching called graining. The methods used are many, almost all indirect, that is with a biting process. In the classic one, a powder of resins, tipycally colophony, or tar is nebulized inside a box which contains the plate. The plate, on which the powder has settled, is then heated to a high temperature to melt the resin and make it stick to the plate. There will be tiny points covered and tiny points uncovered: after the biting process they will respectively correspond to the whites and to the blacks. Zones which must not undergo aquatint, to remain white, or those that have reached the desired shade, are covered by the varnish so that they do not enter in contact with the mordant. With experience and skill in graining and in using the biting process, it is possible to obtain any shade. The international abbreviation for this technique is C5. This is a brief description of the main techniques used in classical calcography. It must however be rememberd that many other techniques exist – from pusher to sugar-lift manner, from soft ground etching to strippled engraving, from crayon manner to relief etching, from open biting to dry impression, from Hayter Method to collagraph, from carburundum to electropoint – that make the calcography scene extremely variegated. International symbols Names and symbols refers to the official document, approved by International Federation of Ex-Libris Societies (FISAE) during the XXIX Congress, held in Frederikshanv, Denmark, 2002. Mr. Benoît Junod co-ordinated the works. The Italian version is the official one, as approved by AIE, Italian Society of Ex Libris, during its Board meeting on 29th March 2003.
Mixed techniques must be indicated as individual symbols separated by plus signs, e.g. C2 + C3 + C5 Source | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
|