Etching is traditionally the process of using strong acid or mordant to cut into the unprotected parts of a metal surface to create a design in intaglio (incised) in the metal. In modern manufacturing, other chemicals may be used on other types of material. As a method of printmaking, it is, along with engraving, the most important technique for old master prints, and remains in wide use today. In a number of modern variants such as microfabrication etching and photochemical milling it is a crucial technique in much modern technology, including circuit boards.
In traditional 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 or she 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 (French for "biting") or etchant, or has acid washed over it. The acid "bites" into the metal (it dissolves part of 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 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.
Etching by goldsmiths 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 at least, and may go back to antiquity. The elaborate decoration of armour, in Germany at least, 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. Printmakers from the German-speaking lands and Central Europe perfected the art and transmitted their skills over the Alps and across Europe.
The process as applied to printmaking is believed to have been invented by Daniel Hopfer (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 of Nuremberg. An Augsburg horse armour in the German Historical Museum, Berlin, dating to between 1512 and 1515, is decorated with motifs from Hopfer's etchings and woodcuts, 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 oldest dated etching is by Albrecht Dürer in 1515, although he returned to engraving after six etchings instead of developing the craft.
The switch to copper plates was probably made in Italy, and thereafter etching soon came to challenge engraving as the most popular medium for artists in printmaking. Its great advantage was that, unlike engraving where the difficult technique for using the burin requires special skill in metalworking, the basic technique for creating the image on the plate in etching is relatively easy to learn for an artist trained in drawing. On the other hand, the handling of the ground and acid need skill and experience, and are not without health and safety risks, as well as the risk of a ruined plate.
Jacques Callot (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.
Callot also appears to have been responsible for an improved, harder, recipe for the etching ground, using lute-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 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.
Callot 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, 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 and many other masters. In the 18th century, Piranesi, Tiepolo and Daniel Chodowiecki were the best of a smaller number of fine etchers. In the 19th and early 20th century, the Etching revival produced a host of lesser artists, but no really major figures. Etching is still widely practiced today.
Aquatint uses acid-resistant resin to achieve tonal effects.
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. Soft ground can also be used to capture the texture or pattern of fabrics or furs pressed into the soft surface.
Other materials that are not manufactured specifically for etching can be used as grounds or resists. Examples including printing ink, paint, spray paint, oil pastels, candle or bees wax, tacky vinyl or stickers, and permanent markers.
There are some new non-toxic grounds on the market that work differently than typical hard or soft grounds.
Relief etching was invented by William Blake 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, 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.
Carborundum etching (sometimes called carbograph printing) was invented in the mid-20th century by American artists who worked for the WPA. In this technique, a metal plate is first covered with silicon carbide grit and run through an etching press; then a design is drawn on the roughened plate using an acid-resistant medium. After immersion in an acid bath, the resulting plate is printed as a relief print. The roughened surface of the relief permits considerable tonal range, and it is possible to attain a high relief that results in strongly embossed prints.
A waxy acid-resist, known as a ground, is applied to a metal plate, most often copper or zinc but steel 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 asphaltum 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 a solution 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 1 part FeCl3 to 1 part water and 1 part nitric to 3 parts water. The strength of the acid determines the speed of the etching process.
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 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 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.
Growing concerns about the health effects of acids and solvents led to the development of less toxic etching methods 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 nontoxic 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.
Some of the earliest printmaking workshops experimenting with, developing and promoting nontoxic techniques include Grafisk Eksperimentarium, in Copenhagen, Denmark, Edinburgh Printmakers, in Scotland, and New Grounds Print Workshop, in Albuquerque, New Mexico.
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.
Copper is a traditional metal, and is still preferred, for etching, as it bites evenly, holds texture well, and does not distort the color of the ink when wiped. Zinc is cheaper than copper, so preferable for beginners, but it does not bite as cleanly as copper does, and it alters some colors of ink. Steel is growing in popularity as an etching substrate. Increases in the 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 etched prints created early in a numbered series tend to be valued more highly. An artist thus takes the total number of prints he or she wishes to produce into account whenever choosing the metal.
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, waxy 'ground' that resists acid. The printmaker then scratches through the ground with a sharp point, exposing lines of metal which the mordant acid attacks.
Aquatint is a variation giving only tone rather than lines when printed. Particulate resin is evenly distributed on all or parts of 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.
Here designs in a syrupy solution of sugar or Camp Coffee 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.
A mixture of nitric acid and Gum Arabic (or almost never – saliva) which can be dripped, spattered or painted onto a metal surface giving interesting results. A mixture of nitric acid and rosin can also be used.
Printing the plate is done by covering the surface with printing ink, 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; the pressure forces the paper into contact with the ink, transferring the image (c.f., chine-collé). Unfortunately, the pressure also subtly degrades the image in the plate, smoothing the roughened areas and closing the lines; a copper 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 before printing with a harder metal to preserve the surface. Zinc 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.
Foul-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.
The phrase "Want to come up and see my etchings?" is a romantic euphemism by which a person entices someone to come back to their place with an offer to look at something artistic, but with ulterior motives. The phrase is a corruption of some phrases in a novel by Horatio Alger, Jr. 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 1929 James Thurber cartoon in which a man tells a woman in a building lobby: "You wait here and I'll bring the etchings down". It was also referenced in Dashiell Hammett's 1934 novel The Thin Man, in which the narrator answers his wife asking him about a lady he had wandered off with by saying: "She just wanted to show me some French etchings."
The phrase was given new popularity in 1937: in a well publicized case, violinist David Rubinoff was accused of inviting a young woman to his hotel room to view some French etchings, but instead seducing her.
As early as 1895, Hjalmar Söderberg used the reference in his "decadent" début novel Delusions (swe: Förvillelser), when he lets the dandy Johannes Hall lure the main character's younger sister Greta into his room under the pretence that they browse through his etchings and engravings (e.g., Die Sünde by Franz Stuck).
Aquatint is an intaglio printmaking technique, a variant of etching that only produces areas of tone rather than lines. For this reason it has mostly been used in conjunction with etching, to give outlines. It has also been used historically to achieve prints in colour, both by printing with multiple plates in different colours, and by making monochrome prints that were then hand-coloured with watercolour.
It has been in regular use since the later 18th century, and was most widely used between about 1770 and 1830, when it was used both for artistic prints and decorative ones. After about 1830 it lost ground to lithography and other techniques. There have been periodic revivals among artists subsequently. The aquatint plate wears out relatively quickly, and is less easily reworked than other intaglio plates; many of Goya's plates were reprinted too often posthumously, giving very poor impressions.Among the most famous prints using the aquatint technique are the major series by Goya, many of The Birds of America by John James Audubon (with the colour added by hand), and prints by Mary Cassatt printed in colour using several plates.Chemical milling
Chemical milling or industrial etching is the subtractive manufacturing process of using baths of temperature-regulated etching chemicals to remove material to create an object with the desired shape. It is mostly used on metals, though other materials are increasingly important. It was developed from armor-decorating and printing etching processes developed during the Renaissance as alternatives to engraving on metal. The process essentially involves bathing the cutting areas in a corrosive chemical known as an etchant, which reacts with the material in the area to be cut and causes the solid material to be dissolved; inert substances known as maskants are used to protect specific areas of the material as resists.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.
For many etch steps, part of the wafer is protected from the etchant by a "masking" material which resists etching. In some cases, the masking material is a photoresist which has been patterned using photolithography. Other situations require a more durable mask, such as silicon nitride.Etching revival
The Etching Revival is the re-emergence and invigoration of etching as an original form of printmaking during a period of time stretching approximately from 1850 to 1930.Glass etching
Glass etching comprises the techniques of creating art on the surface of glass by applying acidic, caustic, or abrasive substances. Traditionally this is done after the glass is blown or cast, although mold-etching has replaced some forms of surface etching. The removal of minute amounts of glass causes the characteristic rough surface and translucent quality of frosted glass.Intaglio (printmaking)
Intaglio ( in-TAL-ee-oh; Italian: [inˈtaʎʎo]) is the family of printing and printmaking techniques in which the image is incised into a surface and the incised line or sunken area holds the ink. It is the direct opposite of a relief print.
Normally, copper or zinc plates are used as a surface or matrix, and the incisions are created by etching, engraving, drypoint, aquatint or mezzotint. Collagraphs may also be printed as intaglio plates.Joseph and Potiphar's Wife (etching)
Joseph and Potiphar's Wife is a 1634 etching by Rembrandt (Bartsch 39). It depicts a story from the Bible, wherein Potiphar's Wife attempts to seduce Joseph. It is signed and dated "Rembrandt f. 1634" (f. for fecit or "made this"), and exists in two states.Liposuction
Liposuction, or simply lipo, is a type of fat removal procedure used in plastic surgery. Evidence does not support an effect on weight beyond a couple of months and it does not appear to affect obesity related problems. In the United States it is the most commonly done cosmetic surgery.Serious complications include deep vein thrombosis, organ perforation, bleeding, and infection. Death occurs in about one per ten thousand cases.The procedure may be performed under general, regional, or local anesthesia. It then involves using a cannula and negative pressure to suck out fat. It is believed to work best on people with a normal weight and good skin elasticity.While the suctioned fat cells are permanently gone, after a few months overall body fat generally returns to the same level as before treatment. This is despite maintaining the previous diet and exercise regimen. While the fat returned somewhat to the treated area, most of the increased fat occurred in the abdominal area. Visceral fat - the fat surrounding the internal organs - increased, and this condition has been linked to life-shortening diseases such as diabetes, stroke, and heart attack.List of drawings by Rembrandt
The following is a list of drawings by Rembrandt that are generally accepted as autograph.Microelectromechanical systems
Microelectromechanical systems (MEMS, also written as micro-electro-mechanical, MicroElectroMechanical or microelectronic and microelectromechanical systems and the related micromechatronics) is the technology of microscopic devices, particularly those with moving parts. It merges at the nano-scale into nanoelectromechanical systems (NEMS) and nanotechnology. MEMS are also referred to as micromachines in Japan, or micro systems technology (MST) in Europe.
MEMS are made up of components between 1 and 100 micrometers in size (i.e., 0.001 to 0.1 mm), and MEMS devices generally range in size from 20 micrometres to a millimetre (i.e., 0.02 to 1.0 mm), although components arranged in arrays (e.g., digital micromirror devices) can be more than 1000 mm2.
They usually consist of a central unit that processes data (the microprocessor) and several components that interact with the surroundings such as microsensors. Because of the large surface area to volume ratio of MEMS, forces produced by ambient electromagnetism (e.g., electrostatic charges and magnetic moments), and fluid dynamics (e.g., surface tension and viscosity) are more important design considerations than with larger scale mechanical devices. MEMS technology is distinguished from molecular nanotechnology or molecular electronics in that the latter must also consider surface chemistry.
The potential of very small machines was appreciated before the technology existed that could make them (see, for example, Richard Feynman's famous 1959 lecture There's Plenty of Room at the Bottom). MEMS became practical once they could be fabricated using modified semiconductor device fabrication technologies, normally used to make electronics. These include molding and plating, wet etching (KOH, TMAH) and dry etching (RIE and DRIE), electro discharge machining (EDM), and other technologies capable of manufacturing small devices. An early example of a MEMS device is the resonistor, an electromechanical monolithic resonator patented by Raymond J. Wilfinger, and the resonant gate transistor developed by Harvey C. Nathanson.Peking glass
Peking glass (also known as Qianlong Glass or Tao Liao Ping) is a form of Chinese glassware that originated in 18th century Peking, China. Originally used in the fabrication of glass snuff bottles, Peking glass has since been appropriated for a number of uses and continues to be produced in China.Photochemical machining
Photochemical machining (PCM), also known as photochemical milling or photo etching, is a chemical milling process used to fabricate sheet metal components using a photoresist and etchants to corrosively machine away selected areas. This process emerged in the 1960s as an offshoot of the printed circuit board industry. Photo etching can produce highly complex parts with very fine detail accurately and economically.
This process can offer economical alternatives to stamping, punching, laser or water jet cutting, or wire electrical discharge machining (EDM) for thin gauge precision parts. The tooling is inexpensive and quickly produced. This makes the process useful for prototyping and allows for easy changes in mass production. It maintains dimensional tolerances and does not create burrs or sharp edges. It can make a part in hours after receiving the drawing.
PCM can be used on virtually any commercially available metal or alloy, of any hardness. It is limited to materials with a thickness of 0.0005 to 0.080 in (0.013 to 2.032 mm). Metals include aluminium, brass, copper, inconel, manganese, nickel, silver, steel, stainless steel, zinc and titanium.
Photochemical machining is a form of photo engraving, and a similar process in microfabrication is called photolithography.Photoengraving
Photoengraving is a process that uses a light-sensitive photoresist applied to the surface to be engraved to create a mask that shields some areas during a subsequent operation which etches, dissolves, or otherwise removes some or all of the material from the unshielded areas. Normally applied to metal, it can also be used on glass, plastic and other materials.
A photoresist is selected which is resistant to the particular acid or other etching compound to be used. It may be a liquid applied by brushing, spraying, pouring or other means and then allowed to set, or it may come in sheet form and be applied by laminating. It is then exposed to light—usually strong ultraviolet (UV) light—through a photographic, mechanically printed, or manually created image or pattern on transparent film. Alternatively, a lens may be used to project an image directly onto it. Typically, the photoresist is hardened where it receives sufficient exposure to light, but some photoresists are initially hard and are then softened by exposure. A solvent is used to wash away the soft parts, laying bare the underlying material, which is then bathed in or sprayed with the acid or other etchant. The remaining photoresist is usually removed after the operation is complete.
In the graphic arts, photoengraving is used to make printing plates for various printing processes, reproducing a wide variety of graphics such as lettering, line drawings and photographs.
The same procedure is used to make printed circuit boards, foil-stamping dies and embossing dies. It is also used to make nameplates, commemorative plaques and other decorative engravings. It can be used to make flat springs, levers, gears and other practical components that would otherwise be fabricated from sheet metal by cutting, drilling, jigsawing or stamping. A very high degree of precision is possible. In these applications, it is properly called photochemical machining, but the terms photochemical milling, chemical milling and photoetching are sometimes used. A similar process called photolithography is used to make integrated circuits.Photolithography
Photolithography, also called optical lithography or UV lithography, is a process used in microfabrication to pattern parts of a thin film or the bulk of a substrate (also called a wafer). It uses light to transfer a geometric pattern from a photomask (also called an optical mask) to a photosensitive (that is, light-sensitive) chemical photoresist on the substrate. A series of chemical treatments then either etches the exposure pattern into the material or enables deposition of a new material in the desired pattern upon the material underneath the photoresist. In complex integrated circuits, a CMOS wafer may go through the photolithographic cycle as many as 50 times.
Photolithography shares some fundamental principles with photography in that the pattern in the photresist etching is created by exposing it to light, either directly (without using a mask) or with a projected image using a photomask. This procedure is comparable to a high precision version of the method used to make printed circuit boards. Subsequent stages in the process have more in common with etching than with lithographic printing. This method can create extremely small patterns, down to a few tens of nanometers in size. It provides precise control of the shape and size of the objects it creates and can create patterns over an entire surface cost-effectively. Its main disadvantages are that it requires a flat substrate to start with, it is not very effective at creating shapes that are not flat, and it can require extremely clean operating conditions. Photolithography is the standard method of printed circuit board (PCB) and microprocessor fabrication.Portrait of Jan Six (etching)
Portrait of Jan Six is a 1647 etching by Rembrandt, known in five states. It shows Jan Six, also the subject of a painted portrait by the same artist.
Adam von Bartsch assigned the etching the number B. 285. Impressions of it are in the British Museum, Hermitage Museum and Rijksmuseum.Printed circuit board
A printed circuit board (PCB) mechanically supports and electrically connects electronic components or electrical components using conductive tracks, pads and other features etched from one or more sheet layers of copper laminated onto and/or between sheet layers of a non-conductive substrate. Components are generally soldered onto the PCB to both electrically connect and mechanically fasten them to it.
Printed circuit boards are used in all but the simplest electronic products. They are also used in some electrical products, such as passive switch boxes.
Alternatives to PCBs include wire wrap and point-to-point construction, both once popular but now rarely used. PCBs require additional design effort to lay out the circuit, but manufacturing and assembly can be automated. Specialized CAD software is available to do much of the work of layout. Mass-producing circuits with PCBs is cheaper and faster than with other wiring methods, as components are mounted and wired in one operation. Large numbers of PCBs can be fabricated at the same time, and the layout only has to be done once. PCBs can also be made manually in small quantities, with reduced benefits.
PCBs can be single-sided (one copper layer), double-sided (two copper layers on both sides of one substrate layer), or multi-layer (outer and inner layers of copper, alternating with layers of substrate). Multi-layer PCBs allow for much higher component density, because circuit traces on the inner layers would otherwise take up surface space between components. The rise in popularity of multilayer PCBs with more than two, and especially with more than four, copper planes was concurrent with the adoption of surface mount technology. However, multilayer PCBs make repair, analysis, and field modification of circuits much more difficult and usually impractical.
The world market for bare PCBs exceeded $60.2 billion in 2014. In 2018, the Global Single Sided Printed Circuit Board Market Analysis Report estimated that the PCB market would reach $79 billion by 2024.Printmaking
Printmaking is the process of creating artworks by printing, normally on paper. Printmaking normally covers only the process of creating prints that have an element of originality, rather than just being a photographic reproduction of a painting. Except in the case of monotyping, the process is capable of producing multiples of the same piece, which is called a print. Each print produced is not considered a "copy" but rather is considered an "original". This is because typically each print varies to an extent due to variables intrinsic to the printmaking process, and also because the imagery of a print is typically not simply a reproduction of another work but rather is often a unique image designed from the start to be expressed in a particular printmaking technique. A print may be known as an impression. Printmaking (other than monotyping) is not chosen only for its ability to produce multiple impressions, but rather for the unique qualities that each of the printmaking processes lends itself to.
Prints are created by transferring ink from a matrix or through a prepared screen to a sheet of paper or other material. Common types of matrices include: metal plates, usually copper or zinc, or polymer plates for engraving or etching; stone, aluminum, or polymer for lithography; blocks of wood for woodcuts and wood engravings; and linoleum for linocuts. Screens made of silk or synthetic fabrics are used for the screenprinting process. Other types of matrix substrates and related processes are discussed below.
Multiple impressions printed from the same matrix form an edition. Since the late 19th century, artists have generally signed individual impressions from an edition and often number the impressions to form a limited edition; the matrix is then destroyed so that no more prints can be produced. Prints may also be printed in book form, such as illustrated books or artist's books.Rembrandt
Rembrandt Harmenszoon van Rijn (; Dutch: [ˈrɛmbrɑnt ˈɦɑrmə(n)soːn vɑn ˈrɛin] (listen); July 15, 1606 – October 4, 1669) was a Dutch draughtsman, painter and printmaker. An innovative and prolific master in three media, he is generally considered one of the greatest visual artists in the history of art and the most important in Dutch art history. Unlike most Dutch masters of the 17th century, Rembrandt's works depict a wide range of style and subject matter, from portraits and self-portraits to landscapes, genre scenes, allegorical and historical scenes, biblical and mythological themes as well as animal studies. His contributions to art came in a period of great wealth and cultural achievement that historians call the Dutch Golden Age, when Dutch art (especially Dutch painting), although in many ways antithetical to the Baroque style that dominated Europe, was extremely prolific and innovative, and gave rise to important new genres. Like many artists of the Dutch Golden Age, such as Jan Vermeer of Delft, Rembrandt was also an avid art collector and dealer.
Rembrandt never went abroad, but he was considerably influenced by the work of the Italian masters and Netherlandish artists who had studied in Italy, like Pieter Lastman, the Utrecht Caravaggists, and Flemish Baroque Peter Paul Rubens. Having achieved youthful success as a portrait painter, Rembrandt's later years were marked by personal tragedy and financial hardships. Yet his etchings and paintings were popular throughout his lifetime, his reputation as an artist remained high, and for twenty years he taught many important Dutch painters.Rembrandt's portraits of his contemporaries, self-portraits and illustrations of scenes from the Bible are regarded as his greatest creative triumphs. His self-portraits form a unique and intimate biography, in which the artist surveyed himself without vanity and with the utmost sincerity. Rembrandt's foremost contribution in the history of printmaking was his transformation of the etching process from a relatively new reproductive technique into a true art form, along with Jacques Callot. His reputation as the greatest etcher in the history of the medium was established in his lifetime and never questioned since. Few of his paintings left the Dutch Republic whilst he lived, but his prints were circulated throughout Europe, and his wider reputation was initially based on them alone.
In his works he exhibited knowledge of classical iconography, which he molded to fit the requirements of his own experience; thus, the depiction of a biblical scene was informed by Rembrandt's knowledge of the specific text, his assimilation of classical composition, and his observations of Amsterdam's Jewish population. Because of his empathy for the human condition, he has been called "one of the great prophets of civilization". The French sculptor Auguste Rodin said, "Compare me with Rembrandt! What sacrilege! With Rembrandt, the colossus of Art! We should prostrate ourselves before Rembrandt and never compare anyone with him!" Vincent van Gogh wrote, "Rembrandt goes so deep into the mysterious that he says things for which there are no words in any language. It is with justice that they call Rembrandt—magician—that's no easy occupation."Sputtering
In physics, sputtering is a phenomenon in which microscopic particles of a solid material are ejected from its surface, after the material is itself bombarded by energetic particles of a plasma or gas. It occurs naturally in outer space, and can be an unwelcome source of wear in precision components. However, the fact that it can be made to act on extremely fine layers of material is exploited in science and industry -- there, it is used to perform precise etching, carry out analytical techniques, and deposit thin film layers in the manufacture of optical coatings, semiconductor devices and nanotechnology products.