Etching
Overview
 
Etching is the process of using strong acid
Acid
An acid is a substance which reacts with a base. Commonly, acids can be identified as tasting sour, reacting with metals such as calcium, and bases like sodium carbonate. Aqueous acids have a pH of less than 7, where an acid of lower pH is typically stronger, and turn blue litmus paper red...

 or mordant
Mordant
A mordant is a substance used to set dyes on fabrics or tissue sections by forming a coordination complex with the dye which then attaches to the fabric or tissue. It may be used for dyeing fabrics, or for intensifying stains in cell or tissue preparations. The term mordant comes from the Latin...

 to cut into the unprotected parts of a metal
Metal
A metal , is an element, compound, or alloy that is a good conductor of both electricity and heat. Metals are usually malleable and shiny, that is they reflect most of incident light...

 surface to create a design in intaglio in the metal (the original process—in modern manufacturing other chemicals may be used on other types of material). As an intaglio
Intaglio (printmaking)
Intaglio is a family of printmaking techniques in which the image is incised into a surface, known as the matrix or plate, and the incised line or area holds the ink. Normally, copper or zinc plates are used as a surface, and the incisions are created by etching, engraving, drypoint, aquatint or...

 method of printmaking
Printmaking
Printmaking is the process of making artworks by printing, normally on paper. Printmaking normally covers only the process of creating prints with an element of originality, rather than just being a photographic reproduction of a painting. Except in the case of monotyping, the process is capable...

, it is, along with engraving
Engraving
Engraving is the practice of incising a design on to a hard, usually flat surface, by cutting grooves into it. The result may be a decorated object in itself, as when silver, gold, steel, or glass are engraved, or may provide an intaglio printing plate, of copper or another metal, for printing...

, the most important technique for old master print
Old master print
An old master print is a work of art produced by a printing process within the Western tradition . A date of about 1830 is usually taken as marking the end of the period whose prints are covered by this term. The main techniques concerned are woodcut, engraving and etching, although there are...

s, and remains widely used today.
In pure etching, a metal (usually copper, zinc or steel) plate is covered with a waxy ground which is resistant to acid.
Encyclopedia
Etching is the process of using strong acid
Acid
An acid is a substance which reacts with a base. Commonly, acids can be identified as tasting sour, reacting with metals such as calcium, and bases like sodium carbonate. Aqueous acids have a pH of less than 7, where an acid of lower pH is typically stronger, and turn blue litmus paper red...

 or mordant
Mordant
A mordant is a substance used to set dyes on fabrics or tissue sections by forming a coordination complex with the dye which then attaches to the fabric or tissue. It may be used for dyeing fabrics, or for intensifying stains in cell or tissue preparations. The term mordant comes from the Latin...

 to cut into the unprotected parts of a metal
Metal
A metal , is an element, compound, or alloy that is a good conductor of both electricity and heat. Metals are usually malleable and shiny, that is they reflect most of incident light...

 surface to create a design in intaglio in the metal (the original process—in modern manufacturing other chemicals may be used on other types of material). As an intaglio
Intaglio (printmaking)
Intaglio is a family of printmaking techniques in which the image is incised into a surface, known as the matrix or plate, and the incised line or area holds the ink. Normally, copper or zinc plates are used as a surface, and the incisions are created by etching, engraving, drypoint, aquatint or...

 method of printmaking
Printmaking
Printmaking is the process of making artworks by printing, normally on paper. Printmaking normally covers only the process of creating prints with an element of originality, rather than just being a photographic reproduction of a painting. Except in the case of monotyping, the process is capable...

, it is, along with engraving
Engraving
Engraving is the practice of incising a design on to a hard, usually flat surface, by cutting grooves into it. The result may be a decorated object in itself, as when silver, gold, steel, or glass are engraved, or may provide an intaglio printing plate, of copper or another metal, for printing...

, the most important technique for old master print
Old master print
An old master print is a work of art produced by a printing process within the Western tradition . A date of about 1830 is usually taken as marking the end of the period whose prints are covered by this term. The main techniques concerned are woodcut, engraving and etching, although there are...

s, and remains widely used today.

Basic method

In pure etching, a metal (usually copper, zinc or steel) plate is covered with a waxy ground which is resistant to acid. The artist then scratches off the ground with a pointed etching needle where he wants a line to appear in the finished piece, so exposing the bare metal. The échoppe, a tool with a slanted oval section, is also used for "swelling" lines. The plate is then dipped in a bath of acid, technically called the mordant
Mordant
A mordant is a substance used to set dyes on fabrics or tissue sections by forming a coordination complex with the dye which then attaches to the fabric or tissue. It may be used for dyeing fabrics, or for intensifying stains in cell or tissue preparations. The term mordant comes from the Latin...

(French
French language
French is a Romance language spoken as a first language in France, the Romandy region in Switzerland, Wallonia and Brussels in Belgium, Monaco, the regions of Quebec and Acadia in Canada, and by various communities elsewhere. Second-language speakers of French are distributed throughout many parts...

 for "biting") or etchant, or has acid washed over it. The acid "bites" into the metal, where it is exposed, leaving behind lines sunk into the plate. The remaining ground is then cleaned off the plate. The plate is inked all over, and then the ink wiped off the surface, leaving only the ink in the etched lines.

The plate is then put through a high-pressure printing press
Printing press
A printing press is a device for applying pressure to an inked surface resting upon a print medium , thereby transferring the ink...

 together with a sheet of paper (often moistened to soften it). The paper picks up the ink from the etched lines, making a print. The process can be repeated many times; typically several hundred impressions (copies) could be printed before the plate shows much sign of wear. The work on the plate can also be added to by repeating the whole process; this creates an etching which exists in more than one state
State (printmaking)
A state, in printmaking, is a different form of a print, caused by a deliberate and permanent change to a matrix such as a copper plate or woodblock ....

.

Etching has often been combined with other intaglio techniques such as engraving (e.g. Rembrandt) or aquatint (e.g. Goya).

History


Origin

Etching by goldsmith
Goldsmith
A goldsmith is a metalworker who specializes in working with gold and other precious metals. Since ancient times the techniques of a goldsmith have evolved very little in order to produce items of jewelry of quality standards. In modern times actual goldsmiths are rare...

s and other metal-workers in order to decorate metal items such as guns, armour, cups and plates has been known in Europe since the Middle Ages
Middle Ages
The Middle Ages is a periodization of European history from the 5th century to the 15th century. The Middle Ages follows the fall of the Western Roman Empire in 476 and precedes the Early Modern Era. It is the middle period of a three-period division of Western history: Classic, Medieval and Modern...

 at least, and may go back to antiquity. The elaborate decoration of armour, in Germany anyway, was an art probably imported from Italy around the end of the 15th century—little earlier than the birth of etching as a printmaking technique. The process as applied to printmaking is believed to have been invented by Daniel Hopfer
Daniel Hopfer
Daniel Hopfer was a German artist who is widely believed to have been the first to use etching in printmaking, at the end of the fifteenth century...

 (circa 1470–1536) of Augsburg, Germany. Hopfer was a craftsman who decorated armour in this way, and applied the method to printmaking, using iron plates (many of which still exist). Apart from his prints, there are two proven examples of his work on armour: a shield from 1536 now in the Real Armeria of Madrid and a sword in the Germanisches Nationalmuseum
Germanisches Nationalmuseum
The Germanisches Nationalmuseum is a museum in Nuremberg, Germany. Founded in 1852, houses a large collection of items relating to German culture and art extending from prehistoric times through to the present day...

 of Nuremberg. An Augsburg horse armour in the German Historical Museum, Berlin
Berlin
Berlin is the capital city of Germany and is one of the 16 states of Germany. With a population of 3.45 million people, Berlin is Germany's largest city. It is the second most populous city proper and the seventh most populous urban area in the European Union...

, dating to between 1512 and 1515, is decorated with motifs from Hopfer's etchings and woodcut
Woodcut
Woodcut—occasionally known as xylography—is a relief printing artistic technique in printmaking in which an image is carved into the surface of a block of wood, with the printing parts remaining level with the surface while the non-printing parts are removed, typically with gouges...

s, but this is no evidence that Hopfer himself worked on it, as his decorative prints were largely produced as patterns for other craftsmen in various media. The switch to copper plates was probably made in Italy, and thereafter etching soon came to challenge engraving
Engraving
Engraving is the practice of incising a design on to a hard, usually flat surface, by cutting grooves into it. The result may be a decorated object in itself, as when silver, gold, steel, or glass are engraved, or may provide an intaglio printing plate, of copper or another metal, for printing...

 as the most popular medium for artists in printmaking
Printmaking
Printmaking is the process of making artworks by printing, normally on paper. Printmaking normally covers only the process of creating prints with an element of originality, rather than just being a photographic reproduction of a painting. Except in the case of monotyping, the process is capable...

. Its great advantage was that, unlike engraving which requires special skill in metalworking, etching is relatively easy to learn for an artist trained in drawing.

Callot's innovations: échoppe, hard ground, stopping-out

Jacques Callot
Jacques Callot
Jacques Callot was a baroque printmaker and draftsman from the Duchy of Lorraine . He is an important figure in the development of the old master print...

 (1592–1635) from Nancy in Lorraine (now part of France) made important technical advances in etching technique. He developed the échoppe, a type of etching-needle with a slanting oval section at the end, which enabled etchers to create a swelling line, as engravers were able to do.
He also seems to have been responsible for an improved, harder, recipe for the etching ground, using lute
Lute
Lute can refer generally to any plucked string instrument with a neck and a deep round back, or more specifically to an instrument from the family of European lutes....

-makers' varnish rather than a wax-based formula. This enabled lines to be more deeply bitten, prolonging the life of the plate in printing, and also greatly reducing the risk of "foul-biting", where acid gets through the ground to the plate where it is not intended to, producing spots or blotches on the image. Previously the risk of foul-biting had always been at the back of an etcher's mind, preventing him from investing too much time on a single plate that risked being ruined in the biting process. Now etchers could do the highly detailed work that was previously the monopoly of engravers, and Callot made full use of the new possibilities.

He also made more extensive and sophisticated use of multiple "stoppings-out" than previous etchers had done. This is the technique of letting the acid bite lightly over the whole plate, then stopping-out those parts of the work which the artist wishes to keep light in tone by covering them with ground before bathing the plate in acid again. He achieved unprecedented subtlety in effects of distance and light and shade by careful control of this process. Most of his prints were relatively small—up to about six inches or 15 cm on their longest dimension, but packed with detail.

One of his followers, the Parisian Abraham Bosse
Abraham Bosse
Abraham Bosse was a French artist, mainly as a printmaker in etching, but also in watercolour.-Life:...

, spread Callot's innovations all over Europe with the first published manual of etching, which was translated into Italian, Dutch, German and English.

The 17th century was the great age of etching, with Rembrandt, Giovanni Benedetto Castiglione
Giovanni Benedetto Castiglione
Giovanni Benedetto Castiglione was an Italian Baroque artist, painter, printmaker and draftsman, of the Genoese school. He is best known now for his elaborate engravings, and as the inventor of the printmaking technique of monotyping. He was known as Il Grechetto in Italy and in France as Le...

 and many other masters. In the 18th Piranesi, Tiepolo
Giovanni Battista Tiepolo
Giovanni Battista Tiepolo , also known as Gianbattista or Giambattista Tiepolo, was an Italian painter and printmaker from the Republic of Venice...

 and Daniel Chodowiecki
Daniel Chodowiecki
Daniel Niklaus Chodowiecki was a Polish - German painter and printmaker with Huguenot ancestry, who is most famous as an etcher...

 were the best of a smaller number of fine etchers. In the 19th and early-20th century the Etching revival
Etching revival
The Etching Revival is the name given by at the time, and by art historians, to the renaissance of etching as an original form of printmaking during a period of time stretching approximately from 1850 to 1930.-Historical outline:...

 produced a host of lesser artists, but no really major figures. Etching is still widely practiced today.

Variants

Soft-ground etching

Soft-ground etching uses a special softer ground. The artist places a piece of paper (or cloth etc. in modern uses) over the ground and draws on it. The print resembles a drawing.

Relief etching

Relief etching was invented by William Blake
William Blake
William Blake was an English poet, painter, and printmaker. Largely unrecognised during his lifetime, Blake is now considered a seminal figure in the history of both the poetry and visual arts of the Romantic Age...

 in about 1788, and he has been almost the only artist to use it in its original form. However from 1880–1950 a photo-mechanical ("line-block") variant was the dominant form of commercial printing for images. A similar process to etching, but printed as a relief print
Relief print
A relief print is an image created by a printmaking process where protruding surface faces of the matrix are inked; recessed areas are ink free. Printing the image is therefore a relatively simple matter of inking the face of the matrix and bringing it in firm contact with the paper...

, so it is the "white" background areas which are exposed to the acid, and the areas to print "black" which are covered with ground. Blake's exact technique remains controversial. He used the technique to print texts and images together, writing the text and drawing lines with an acid-resistant medium.

Modern technique in detail

A waxy acid-resist, known as a ground, is applied to a metal plate, most often copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...

 or zinc
Zinc
Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...

 but steel
Steel
Steel is an alloy that consists mostly of iron and has a carbon content between 0.2% and 2.1% by weight, depending on the grade. Carbon is the most common alloying material for iron, but various other alloying elements are used, such as manganese, chromium, vanadium, and tungsten...

 plate is another medium with different qualities. There are two common types of ground: hard ground and soft ground.

Hard ground can be applied in two ways. Solid hard ground comes in a hard waxy block. To apply hard ground of this variety, the plate to be etched is placed upon a hot-plate (set at 70 degrees C), a kind of metal worktop that is heated up. The plate heats up and the ground is applied by hand, melting onto the plate as it is applied. The ground is spread over the plate as evenly as possible using a roller. Once applied the etching plate is removed from the hot-plate and allowed to cool which hardens the ground.

After the ground has hardened the artist "smokes" the plate, classically with 3 beeswax tapers, applying the flame to the plate to darken the ground and make it easier to see what parts of the plate are exposed. Smoking not only darkens the plate but adds a small amount of wax. Afterwards the artist uses a sharp tool to scratch into the ground, exposing the metal.
The second way to apply hard ground is by liquid hard ground. This comes in a can and is applied with a brush upon the plate to be etched. Exposed to air the hard ground will harden. Some printmakers use
oil/tar based asphaltumhttp://www.magical-secrets.com/studio/glossary or
bitumen as hard ground, although often bitumen is used to protect steel plates from rust and copper plates from aging.

Soft ground also comes in liquid form and is allowed to dry but it does not dry hard like hard ground and is impressionable.
After the soft ground has dried the printmaker may apply materials such as leaves, objects, hand prints and so on which will penetrate the soft ground and expose the plate underneath.

The ground can also be applied in a fine mist, using powdered rosin or spraypaint. This process is called aquatint, and allows for the creation of tones, shadows, and solid areas of color.

The design is then drawn (in reverse) with an etching-needle or échoppe. An "echoppe" point can be made from an ordinary tempered steel etching needle, by grinding the point back on a carborundum stone, at a 45–60 degree angle. The "echoppe" works on the same principle that makes a fountain pen's line more attractive than a ballpoint's: The slight swelling variation caused by the natural movement of the hand "warms up" the line, and although hardly noticeable in any individual line, has a very attractive overall effect on the finished plate. It can be drawn with in the same way as an ordinary needle

The plate is then completely submerged in an acid that eats away at the exposed metal. Ferric chloride may be used for etching copper or zinc plates, whereas nitric acid may be used for etching zinc or steel plates. Typical solutions are 2 parts FeCl3 to 2 parts water and 1 part nitric to 3 parts water. The strength of the acid determines the speed of the etching process.
  • The etching process is known as biting (see also spit-biting below).
  • The waxy resist prevents the acid
    Acid
    An acid is a substance which reacts with a base. Commonly, acids can be identified as tasting sour, reacting with metals such as calcium, and bases like sodium carbonate. Aqueous acids have a pH of less than 7, where an acid of lower pH is typically stronger, and turn blue litmus paper red...

     from biting the parts of the plate which have been covered.
  • The longer the plate remains in the acid the deeper the "bites" become.

During the etching process the printmaker uses a bird feather or similar item to wave away bubbles and detritus produced by the dissolving process, from the surface of the plate, or the plate may be periodically lifted from the acid bath. If a bubble is allowed to remain on the plate then it will stop the acid biting into the plate where the bubble touches it. Zinc produces more bubbles much more rapidly than copper and steel and some artists use this to produce interesting round bubble-like circles within their prints for a Milky Way effect.

The detritus is powdery dissolved metal that fills the etched grooves and can also block the acid from biting evenly into the exposed plate surfaces. Another way to remove detritus from a plate is to place the plate to be etched face down within the acid upon plasticine balls or marbles, although the drawback of this technique is the exposure to bubbles and the inability to remove them readily.

For aquatinting a printmaker will often use a test strip of metal about a centimetre to three centimetres wide. The strip will be dipped into the acid for a specific number of minutes or seconds. The metal strip will then be removed and the acid washed off with water. Part of the strip will be covered in ground and then the strip is redipped into the acid and the process repeated. The ground will then be removed from the strip and the strip inked up and printed. This will show the printmaker the different degrees or depths of the etch, and therefore the strength of the ink color, based upon how long the plate is left in the acid.

The plate is removed from the acid and washed over with water to remove the acid. The ground is removed with a solvent such as turpentine
Turpentine
Turpentine is a fluid obtained by the distillation of resin obtained from trees, mainly pine trees. It is composed of terpenes, mainly the monoterpenes alpha-pinene and beta-pinene...

. Turpentine is often removed from the plate using methylated spirits since turpentine is greasy and can affect the application of ink and the printing of the plate.

Spit-biting is a process whereby the printmaker will apply acid to a plate with a brush in certain areas of the plate. The plate may be aquatinted for this purpose or exposed directly to the acid. The process is known as "spit"-biting due to the use of saliva once used as a medium to dilute the acid, although gum arabic or water are now commonly used.

A piece of matte board, a plastic "card", or a wad of cloth is often used to push the ink into the incised lines. The surface is wiped clean with a piece of stiff fabric known as tarlatan and then wiped with newsprint
Newsprint
Newsprint is a low-cost, non-archival paper most commonly used to print newspapers, and other publications and advertising material. It usually has an off-white cast and distinctive feel. It is designed for use in printing presses that employ a long web of paper rather than individual sheets of...

 paper; some printmakers prefer to use the blade part of their hand or palm at the base of their thumb. The wiping leaves ink in the incisions. You may also use a folded piece of organza silk to do the final wipe. If copper or zinc plates are used, then the plate surface is left very clean and therefore white in the print. If steel plate is used, then the plate's natural tooth gives the print a grey background similar to the effects of aquatinting. As a result steel plates do not need aquatinting as gradual exposure of the plate via successive dips into acid will produce the same result.

A damp piece of paper is placed over the plate and it is run through the press.

Non-toxic etching

Growing concerns about the health effects of acids and solvents
http://web.princeton.edu/sites/ehs/artsafety/sec13.htm
http://www.chicagoartistsresource.org/node/9287
led to the development of less toxic etching methods http://www.greenart.info/galvetch/etchtabl.htm
in the late 20th century. An early innovation was the use of floor wax as a hard ground for coating the plate. Others, such as printmakers Mark Zaffron and Keith Howard, developed systems using acrylic polymers as a ground and ferric chloride for etching. The polymers are removed with sodium carbonate (washing soda) solution, rather than solvents. When used for etching, ferric chloride does not produce a corrosive gas, as acids do, thus eliminating another danger of traditional etching.

The traditional aquatint, which uses either powdered rosin or enamel spray paint, is replaced with an airbrush application of the acrylic polymer hard ground. Again, no solvents are needed beyond the soda ash solution, though a ventilation hood is needed due to acrylic particulates from the air brush spray.

The traditional soft ground, requiring solvents for removal from the plate, is replaced with water-based relief printing ink. The ink receives impressions like traditional soft ground, resists the ferric chloride etchant, yet can be cleaned up with warm water and either soda ash solution or ammonia.

Anodic etching has been used in industrial processes for over a century. The etching power is a source of direct current. The item to be etched (anode) is connected to its positive pole. A receiver plate (cathode) is connected to its negative pole. Both, spaced slightly apart, are immersed in a suitable aqueous solution of a suitable electrolyte. The current pushes the metal out from the anode into solution and deposits it as metal on the cathode. Shortly before 1990, two groups working independently developed different ways of applying it to creating intaglio printing plates.

In the patented Electroetch system, invented by Marion and Omri Behr, in contrast to certain non toxic etching methods, an etched plate can be reworked as often as the artist desires The system uses voltages below 2 volts which exposes the uneven metal crystals in the etched areas resulting in superior ink retention and printed image appearance of quality equivalent to traditional acid methods. With polarity reversed the low voltage provides a simpler method of making mezzotint plates as well as the "steel facing" copper plates.

Photo-etching


Light sensitive polymer plates allow for photorealistic etchings. A photo-sensitive coating is applied to the plate by either the plate supplier or the artist. Light is projected onto the plate as a negative image to expose it. Photopolymer plates are either washed in hot water or under other chemicals according to the plate manufacturers' instructions. Areas of the photo-etch image may be stopped-out before etching to exclude them from the final image on the plate, or removed or lightened by scraping and burnishing once the plate has been etched. Once the photo-etching process is complete, the plate can be worked further as a normal intaglio plate, using drypoint, further etching, engraving, etc. The final result is an intaglio plate which is printed like any other.

Types of metal plates

Copper is a traditional metal, and is still preferred, for etching, as it bites evenly, holds texture well, and does not distort the colour of the ink when wiped. Zinc is cheaper than copper, so preferable for beginners, but it does not bite as cleanly as copper, and it alters some colours of ink. Steel is growing in popularity as an etching substrate. Prices of copper and zinc have steered steel to an acceptable alternative. The line quality of steel is less fine than copper but finer than zinc. Steel has a natural and rich aquatint.

The type of metal used for the plate impacts the number of prints the plate will produce. The firm pressure of the printing press slowly rubs out the finer details of the image with every pass through. With relatively soft copper, for example, the etching details will begin to wear very quickly, some copper plates show extreme wear after only ten prints. Steel, on the other hand, is incredibly durable. This wearing out of the image over time is one of the reasons prints created early in a numbered series tend to be valued more highly. The total number of prints an artist would like to produce are taken in to account when choosing the metal.

Industrial uses

Etching is also used in the manufacturing of printed circuit board
Printed circuit board
A printed circuit board, or PCB, is used to mechanically support and electrically connect electronic components using conductive pathways, tracks or signal traces etched from copper sheets laminated onto a non-conductive substrate. It is also referred to as printed wiring board or etched wiring...

s and semiconductor device
Semiconductor device
Semiconductor devices are electronic components that exploit the electronic properties of semiconductor materials, principally silicon, germanium, and gallium arsenide, as well as organic semiconductors. Semiconductor devices have replaced thermionic devices in most applications...

s (see Etching (microfabrication)
Etching (microfabrication)
Etching is used in microfabrication to chemically remove layers from the surface of a wafer during manufacturing. Etching is a critically important process module, and every wafer undergoes many etching steps before it is complete....

 ), on glass
Etching (glass)
__FORCETOC__Etching refers to the technique of creating art on the surface of glass by applying acidic, caustic, or abrasive substances. Traditionally this was done after the glass was blown or cast.- Techniques :...

, and in the preparation of metallic specimens for microscopic observation.

Hard grounds

There are many ways for the printmaker to control the acid's effects. Most typically, the surface of the plate is covered in a hard, wax
Wax
thumb|right|[[Cetyl palmitate]], a typical wax ester.Wax refers to a class of chemical compounds that are plastic near ambient temperatures. Characteristically, they melt above 45 °C to give a low viscosity liquid. Waxes are insoluble in water but soluble in organic, nonpolar solvents...

y 'ground' that resists acid. The printmaker then scratches through the ground with a sharp point, exposing lines of metal that are attacked by the acid.

Aquatint

Aquatint
Aquatint
Aquatint is an intaglio printmaking technique, a variant of etching.Intaglio printmaking makes marks on the matrix that are capable of holding ink. The inked plate is passed through a printing press together with a sheet of paper, resulting in a transfer of the ink to the paper...

 is a variation in which particulate resin is evenly distributed on the plate, then heated to form a screen ground of uniform but less than perfect density. After etching, any exposed surface will result in a roughened (i.e. darkened) surface. Areas that are to be light in the final print are protected by varnishing between acid baths. Successive turns of varnishing and placing the plate in acid create areas of tone difficult or impossible to achieve by drawing through a wax ground.

Sugar Lift

Here designs in a syrupy solution of sugar or Camp Coffee
Camp Coffee
Camp Coffee is a Scottish food product, which began production in 1876 by Paterson & Sons Ltd. in a plant on Charlotte St, Glasgow. Almost one-hundred years later in 1974 businessman Daniel Jenks merged with Paterson to form Paterson Jenks plc. In 1984, Paterson Jenks plc was bought by McCormick &...

 are painted onto the metal surface prior to it being coated in a liquid etching ground or 'stop out' varnish. When later the plate is placed in hot water the sugar dissolves and lifts off leaving the image. The plate can then be etched.

Spit Bite

A mixture of nitric acid and Gum Arabic
Gum arabic
220px|thumb|right|Acacia gumGum arabic, also known as acacia gum, chaar gund, char goond, or meska, is a natural gum made of hardened sap taken from two species of the acacia tree; Acacia senegal and Acacia seyal...

 (or almost never - saliva) which can be dripped, spattered or painted onto a metal surface giving interesting results.

Carbograph

This is an etching technique invented in 2006 by the U.S. printmaker Rand Huebsch. Tiny particles of carborundum grit are mixed into the acid-resistant ground, which is brushed onto the bare metal as usual and allowed to dry. When that mixture has dried, the metal stylus is used on the plate and thereby removes some of the grit particles, so that minuscule areas of copper are exposed to the acid and etched; they will eventually hold the ink for the printing process. Thus the image on paper has a texture similar to that of a charcoal drawing.

Printing

Printing the plate is done by covering the surface with ink
Ink
Ink is a liquid or paste that contains pigments and/or dyes and is used to color a surface to produce an image, text, or design. Ink is used for drawing and/or writing with a pen, brush, or quill...

, then rubbing the ink off the surface with tarlatan cloth or newsprint, leaving ink in the roughened areas and lines. Damp paper is placed on the plate, and both are run through a printing press
Printing press
A printing press is a device for applying pressure to an inked surface resting upon a print medium , thereby transferring the ink...

; the pressure forces the paper into contact with the ink, transferring the image (c.f., chine-collé
Chine-collé
Chine-collé is a special technique in printmaking in which the image is transferred to a surface that is bonded to a heavier support in the printing process. One purpose is to allow the printmaker to print on a much more delicate surface, such as Japanese paper or linen, which pulls finer details...

). Unfortunately, the pressure also subtly degrades the image in the plate, smoothing the roughened areas and closing the lines; a copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...

 plate is good for, at most, a few hundred printings of a strongly etched imaged before the degradation is considered too great by the artist. At that point, the artist can manually restore the plate by re-etching it, essentially putting ground back on and retracing their lines; alternatively, plates can be electro-plated
Electroplating
Electroplating is a plating process in which metal ions in a solution are moved by an electric field to coat an electrode. The process uses electrical current to reduce cations of a desired material from a solution and coat a conductive object with a thin layer of the material, such as a metal...

 before printing with a harder metal to preserve the surface. Zinc
Zinc
Zinc , or spelter , is a metallic chemical element; it has the symbol Zn and atomic number 30. It is the first element in group 12 of the periodic table. Zinc is, in some respects, chemically similar to magnesium, because its ion is of similar size and its only common oxidation state is +2...

 is also used, because as a softer metal, etching times are shorter; however, that softness also leads to faster degradation of the image in the press.

Faults

Faux-bite or "over-biting" is common in etching, and is the effect of minuscule amounts of acid leaking through the ground to create minor pitting and burning on the surface. This incidental roughening may be removed by smoothing and polishing the surface, but artists often leave faux-bite, or deliberately court it by handling the plate roughly, because it is viewed as a desirable mark of the process.

"Etchings" cliché


The phrase "Want to come up and see my etchings?" is a romantic cliché in which a man entices a woman to come back to his place with an offer to look at something artistic. The phrase is a corruption of some phrases in a novel by Horatio Alger, Jr.
Horatio Alger, Jr.
Horatio Alger, Jr. was a prolific 19th-century American author, best known for his many formulaic juvenile novels about impoverished boys and their rise from humble backgrounds to lives of middle-class security and comfort through hard work, determination, courage, and honesty...

 called "The Erie Train Boy" which was first published in 1891. Alger was an immensely popular author in the 19th century, especially with young people and his books were widely quoted. In CHAPTER XXII of the book a woman writes to her boyfriend "I have a new collection of etchings that I want to show you. Won't you name an evening when you will call, as I want to be certain to be at home when you really do come." The boyfriend then writes back "I shall no doubt find pleasure in examining the etchings which you hold out as an inducement to call." This was referenced in a James Thurber
James Thurber
James Grover Thurber was an American author, cartoonist and celebrated wit. Thurber was best known for his cartoons and short stories published in The New Yorker magazine.-Life:...

 cartoon where a man tells a woman in a building lobby: "You wait here and I'll bring the etchings down". Also in Dashiell Hammett
Dashiell Hammett
Samuel Dashiell Hammett was an American author of hard-boiled detective novels and short stories, and political activist. Among the enduring characters he created are Sam Spade , Nick and Nora Charles , and the Continental Op .In addition to the significant influence his novels and stories had on...

's 1934 novel The Thin Man
The Thin Man
The Thin Man is a detective novel by Dashiell Hammett, originally published in Redbook. Although he never wrote a sequel, the book became the basis for a successful six-part film series which also began in 1934 with The Thin Man and starred William Powell and Myrna Loy...

, where the narrator answers his wife asking him about a lady he had wandered off with, "She just wanted to show me some French etchings."

See also

  • Electroetching
    Electroetching
    Electroetching is a metal etching process that involves the use of a solution of an electrolyte, an anode and a cathode. The metal piece to be etched is connected to the positive pole of a source of direct electric current. A piece of the same metal is connected to the negative pole of the...

  • Old master prints for the history of the method
  • Acid test (gold)
    Acid test (gold)
    An acid test is any qualitative chemical or metallurgical assay which uses acid; most commonly, and historically, the use of a strong acid to distinguish gold from base metals. Figuratively, acid test is any definitive test for some attribute, e.g...


External links

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