Details

Geschreven door Joop Vegter

Categorie: Ongecategoriseerd

Gepubliceerd: 12 februari 2021

Hits: 545

Deze pagina moet nog gecontroleerd/gerepareerd worden. This page is not yet been controlled/repaired by the webmaster. 
Bron : The Mezzotint Joop Vegter 

The mezzotint

Joop Vegter

The word illezzotint (Italian mezza tinta, "halftone") is used to indicate a graphic technique as well as the print produced by it.
In comparison witli other graphic techniques such as woodcut, etching, lithograph and silkscreen, mezzotint is rarely practised, probably because it is an extrenlely laborious and tillie-consuming technique.

Mezzotint was invented by Ludwig von Siegen (born near Cologne in 1609). Around 1640 he stayed in Amsterdam for some time, where he made his first mezzotint in 1642.
His invention was the roughening of the surface of a copper plate with a 'roulette': this is an instrument with a small wheel covered with sharp points or ridges (see fig. 1).

By rolling this wheel across the copper plate with some pressure, small pits and burrs are thrown up in the copper plate.
Variation in the pressure causes the pits to become deeper or less so.
The result in the print is grey tones ranging from white to black.
By flattening the pits and burrs slightly in certain places, so that they held less ink and left a lighter impression, Ludwig von Siegen managed to give his print a great variety of grey tones blending with each other.
Von Siegen stayed in Amsterdam for several years at the time when Rembrandt lived there, and he may well have known Rembrandt's work.
His first mezzotint from 1642 was the portrait of Countess Amalia Elizabeth of Hesse-Kassel, widow of William V of Hesse-Kassel.
Ludwig von Siegen, himself an officer, had been appointed by her as her chamber esquire.
It is believed that Ludwig von Siegen met Prince Rupert of the Palatine in Brussels in 1654.
The latter was the son of Frederick V and Elizabeth Stuart, king and queen of Bohemia during the winter of 1619-1620.

After her husband's early death Elizabeth - 'the winter queen' - lived in exile in the Netherlands for 40 years.
From his mother's side Prince Rupert was a nephew of Charles Il of England.
It is Ludwig von Siegen who must have taught Prince Rupert the mezzotint technique. In 1658 his first mezzotint "The Great Executioner" appeared, which he made with the assistance of the French graphic artist Wallerant Vaillant after a painting by the Spanish painter De Ribera.

In 1660 Prince Rupert returned to England and introduced the mezzotint, which became a highly popular technique there.
The Dutch graphic artist Abraham Blooteling is credited with having invented the 'rocker' about 1675, although there is evidence that Ludwig von Siegen, too, may already have used the rocker.

The rocker is an instrument which is still used nowadays to make pits and burrs in the copper plate.
Mezzotint was highly suited for making reproductions of paintings and has been applied for that purpose almost exclusively.
There are two heydays: the first one was in the Netherlands in the last quarter of the 17th century with artists like Abraham Blooteling, Jan and Paul van Somer, Jan and Nicolaas Verkolje and Gerard Valk.
The second heyday is the great period of mezzotint: the 18th century in England, featuring important mezzotinters like John Raphael Smith, Richard Earlom, Valentin Green, William Pether, to name just a few.

After the middle of the 19th century the mezzotint technique fell into almost total disuse for making reproductions of paintings, due to the rise of the lithograph and of photographic reproduction techniques in particular.
In the past two or three decades, roughly from 1960/70, interest in mezzotint has been on the increase again world-wide, not only among a number of graphic artists, but also among collectors.
Nowadays mezzotint is used exclusively by artists to make their own, original graphic work.

The process of making a mezzotint can be divided into three stages:

1. the preparation of the copper plate
2. creating the image on the plate
3. printing the plate.

The Preparation

BeÍore making a mezzotint the surface oÍ a copper plate is roughened. The roughening is done in a classical mamer by means of a specially designed instrument: the cradle or rocker (see Íig. 2).
This tool can be described as a broad, short chisel whose sharp side is not straight, but somewhat curved On the sharp side very narrow grooves have been ground into the blade, so that the curved, sharp side consists of many minute, even teeth.
Rockers come in tyPes: the teeth can be coarsel or finer A coarse rocker (no. 40) has 40 teeth per inch (= 16 per cm) and a very Íine rocker (no. 150) has 150 teeth per inch (= 60 PeÍ cm). Also, rockers can be wider or narower, ranging Írom 6 inches (15 cm) to l inch (2.5 cm). The rocker is rocked over the plate manually and with some Pressule in a sideways rocking movement.

With every rocking movement, a row of fine pits lined with minute burrs is made in the copper (see fig 3). During the rocking action the rocker is slowly moved backwards or forwards, depending on the angle oÍ the rocker and the preÍerence of the artist (see Íig. 4).

As a result, a band of zigzags arises, consisting oÍ pits and burrs. Once that band stretches across the entire width oÍ the plate, adjoining bands are rocked parallel to it and overlapping slightly. When the whole copper plate has been roughened in this way, the plate has been rocked in one dÍection only.
Proper roughening requires rocking the plate many times in different directions with constant pressure in as regular a manner as possible.

I myself usually rock the copper plate in Íour directions: horizontally, vertically and both ways diagonally. Then I repeat these four directions 16 to 25 times, which means that the whole plate is worked 64 to 100 times with the rocker. This is a time-consuming job: the Proper rocking oÍ a copper plate size 10 x 10 cm with a Íine-toothed rockel sometimes takes 8 hours. Naturally the teeth oÍ the rocker will wear slightty during this work.

In order to obtain an oPtimal result, i.e. regular pits oÍ approximately identical depth, the rockers must be kept really sharp. As a rule, this implies sharpening the rockeÍ every 10 to 15 minutes. Once the copper plate has been rocked well, the surface is covered with millions oÍ pits and burrs. A plate like this no longer feels like metal, it is velvet to the touch. All these pits and burrs hold a lot oÍ ink when the plate is inked. IÍ we were to print the plate in this stage, the whole print would become velvett deep black.

That is why the Dutch name for mezzotint is zwarte kunst ("black art"), which is nothing to do with magic but everything with that sumptuous, deep black colour. lt stands to reason that other methods have been sought to replace the rocking, which consumes so much strength, time and patience

Without going into them more deeply I mention iust a few methods: - mechanically rocked plates; these are supplied by a Japanese firm; - providing the copper Plate with a dense network oÍ drypoint tines; this gives the Print a special fabdc-like texture (see mezzotint no. 24); - running the copper plate covered with coarse carbodonum sandpaper (no. 80) through the etching Press under pressure, and repeating this some 50 times. Unless sPecial precautions are taken, this method is detlimental to the Press (see mezzotint no. 10); - biting the whole copPer Plate with aquatint oÍ the blackest possible degree (this produces no burrs, but only Pits in the plate); - sandblasting the copper plate (drawback: the Plate warps easily).

Creating the image on the Plate
Mezzotint is a 'tonal process'. The picturc, the image of a mezzotint is composed of tonal values, i.e gradations of light and dark rather than lines. Typical of a mezzotint in bÈck - a 'manière noire' print - is the Possibility of showing a smooth graduation Írom dch velvety black to bright white' To create an image on the rocked copper plate, one can stalt Írom a drawing or a sketch or work dircctly on the Plate' When staÍting from a sketch, it is convenient if the sketch has been conceived in tonal values, while the contours of the shapes have been indicated as well. The idea is Íor the contours to aPPear on the Plate mirrored This can be achieved inter alia by copying the contours on transparent drawing-paper and reversing this transpaÍent papei so that one sees the mirror image By means of carbon

paper these mirrored contours are drawn on the copper plaie. Now the desiSn in all its tonal values is created on the iocked plate by more or less scraping away or burnishing the bulrs and pits in places. The flatter the buÍs, the shallower the pits, the less the amount of ink held aÍter inking, which results in lighter tones when Printing (see fig 5)' As there rnay be an endless variation in the height and depth of the burrs and Pits resPectively, it is possible to create a great many greys blending with eac} other in a mezzotint' ihe plate can also be highty polished in places so that it will print white. Flattening the burrs and pits is done by means of'scrapers, 'burnishers' and polishers oÍ agate. A scraper is triangular, oÍ steel, and tapered (see fig. 1). lt has three sharP edges; the edges are used to scraPe away or abrade some of the burrs onlhe rocked copper plate This is why the German word for mezzotint is Schabkunst The more material is scraPed away, the lighter that patch will come out when printed' Thus, when makir1g a mezzotint one works Írom black to white. A burnisher is a smoothly polished piece oÍ steel, with a somewhat rounded end. It is often combined with the scraper into one tool. The burnisher is lrsed to flatten the bu s more or less; no copPer is scraped away, then The burrs become a bit flatter and are pressed into the Pits slightly, which also results in a liShter tone in the Print' The diÍÍerence between this operation and scraping is that a burnished patch pÍoduces a grey in the print with a somewhat moÍe irregular texture. The polisher of agate is mostly used to polish to near or complete smoothness those Patches on the copper Plate that must be almost white or absolutely white in the pdnt For fine details I often work with dentist's tools, sometimes reshaped into minute scrapers ol burnishers Occasionally I use arlold dental engine for polishing with small polishing discs. lt is possible to some extent to check on the copper plate whether all desired tonal values have been actually attained by scraping, burnishing and polishing More gleam on the copper plate implies a lighter tone on the relevant patch oÍ the Print One gets a better check by

making a proof. Removing material is easier than replacing it: hence it is oÍ paramount imPortance that one pÍoceed very cautiously when working from black to white. It is better to scrape away or burnish too little and then to make a proof than to scrape away too much and to Produce too light an area. It is always possible to make a grey on the copPer plate lighter, whereas the reverse is very diÍficult if not impossible. Printing Once the image with all its shades of grey is on the copper plate, it can be printed after having been inked. A mezzotint is pdnted on an etching press, almost in the same manner as an etching, an aquatint or a dryPoint. The whole plate is covered with etching ink. A leather dabbeÍ is used to dab the ink to an even coat, ensuring that it is also forced well into even the smallest pits. Subsequently any excess ink is wiped by hand. Here the difference with dÍypoint or etching is that although mezzotint is an intaglio technique, the Parts that aÍe to remain free from ink lie deeper than those which do hold ink (see Íig. 6).

The wiping must be done with the palm of the hand; if one uses cheesecloth or tarlatan for this or PaPeÍ, as usual when inking etchings, the many burrs on the coPPeÍ plate will tear off tiny fibres which mix with the ink, thus rendering the ink useless. Finally, the mezzotint copper plate is run thlough the etching pÍess along with a sheet oÍ previously dampened etching paper. The edition oÍ a Í\ezzoti^t, printed from a copper plate, is Iimited: due to the pressure of the etching press the burrs wear oÍÍ soon. Still, it is possible to make 50 to 100 good prints. A bigger edition can be printed only íaom steelfaced plates. By means oÍ electrolysis a very thin coat of iron several microns thick can be applied onto the coPPer Plate. A steelfaced plate can produce up to 500 good pÍints. Colour mezzotint A colour mezzotint is usually made oÍ 3 to 4 plates: one foÍ yellow, one for magenta red, and one for cyan blue; another plate can be added Íor an (almost) black colour. Any desired hue can be obtained with these basic colours. I usually staÍt a colour mezzotint with a sketch in colour: in water-colout in acrylic, sometimes in coloured crayon. AII 3 or 4 plates are processed according to the mezzotint technique described above. Every desired colour indicated on the sketch is split up on the face of it into the 3 or 4 basic colours. For example: if the final print is to show a dark olive green in a particular area, then one must scraPe away or burnish almost nothing theÍe on the yellow plate, on the magenta plate one must burnish/scrape away a sizeable amount, but some red must remain; on the cyan blue Plate one must scrape away/burnish to medium blue, whereas, finally, a light grey must remain on the black plate. The images on these 3 or 4 plates do have to fit onto each other exactly. \Arhen one first prints the yellow plate, then the magenta red one, then the cyan blue one and finally the black plate, the area thus processed will show a dark olive green colour in the pÍint.