Lithography

Lithography is a method of printing originally based on the immiscibility of oil and water. The printing is from a stone (lithographic limestone) or a metal plate with a smooth surface. It was invented in 1796 by German author and actor Alois Senefelder as a cheap method of publishing theatrical works. Lithography can be used to print text or artwork onto paper or other suitable material.

Lithography originally used an image drawn with oil, fat, or wax onto the surface of a smooth, level lithographic limestone plate. The stone was treated with a mixture of acid and gum arabic, etching the portions of the stone that were not protected by the grease-based image. When the stone was subsequently moistened, these etched areas retained water; an oil-based ink could then be applied and would be repelled by the water, sticking only to the original drawing. The ink would finally be transferred to a blank paper sheet, producing a printed page. This traditional technique is still used in some fine art printmaking applications.

In modern lithography, the image is made of a polymer coating applied to a flexible plastic or metal plate. The image can be printed directly from the plate (the orientation of the image is reversed), or it can be offset, by transferring the image onto a flexible sheet (rubber) for printing and publication.

As a printing technology, lithography is different from intaglio printing (gravure), wherein a plate is either engraved, etched, or stippled to score cavities to contain the printing ink; and woodblock printing or letterpress printing, wherein ink is applied to the raised surfaces of letters or images. Today, most types of high-volume books and magazines, especially when illustrated in colour, are printed with offset lithography, which has become the most common form of printing technology since the 1960s.
The related term “photolithography” refers to when photographic images are used in lithographic printing, whether these images are printed directly from a stone or from a metal plate, as in offset printing. “Photolithography” is used synonymously with “offset printing”. The technique as well as the term were introduced in Europe in the 1850s. Beginning in the 1960s, photolithography has played an important role in the fabrication and mass production of integrated circuits in the microelectronics industry.

The principle of lithography
Lithography uses simple chemical processes to create an image. For instance, the positive part of an image is a water-repelling (“hydrophobic”) substance, while the negative image would be water-retaining (“hydrophilic”). Thus, when the plate is introduced to a compatible printing ink and water mixture, the ink will adhere to the positive image and the water will clean the negative image. This allows a flat print plate to be used, enabling much longer and more detailed print runs than the older physical methods of printing (e.g., intaglio printing, letterpress printing).

Lithography was invented by Alois Senefelder in the Kingdom of Bavaria in 1796. In the early days of lithography, a smooth piece of limestone was used (hence the name “lithography”: “lithos” (λιθος) is the ancient Greek word for stone). After the oil-based image was put on the surface, a solution of gum arabic in water was applied, the gum sticking only to the non-oily surface. During printing, water adhered to the gum arabic surfaces and was repelled by the oily parts, while the oily ink used for printing did the opposite.

Lithography on limestone
Lithography works because of the mutual repulsion of oil and water. The image is drawn on the surface of the print plate with a fat or oil-based medium (hydrophobic) such as a wax crayon, which may be pigmented to make the drawing visible. A wide range of oil-based media is available, but the durability of the image on the stone depends on the lipid content of the material being used, and its ability to withstand water and acid. After the drawing of the image, an aqueous solution of gum arabic, weakly acidified with nitric acid HNO3 is applied to the stone. The function of this solution is to create a hydrophilic layer of calcium nitrate salt, Ca(NO3)2, and gum arabic on all non-image surfaces. The gum solution penetrates into the pores of the stone, completely surrounding the original image with a hydrophilic layer that will not accept the printing ink. Using lithographic turpentine, the printer then removes any excess of the greasy drawing material, but a hydrophobic molecular film of it remains tightly bonded to the surface of the stone, rejecting the gum arabic and water, but ready to accept the oily ink.

When printing, the stone is kept wet with water. Naturally the water is attracted to the layer of gum and salt created by the acid wash. Printing ink based on drying oils such as linseed oil and varnish loaded with pigment is then rolled over the surface. The water repels the greasy ink but the hydrophobic areas left by the original drawing material accept it. When the hydrophobic image is loaded with ink, the stone and paper are run through a press that applies even pressure over the surface, transferring the ink to the paper and off the stone.

Senefelder had experimented during the early 19th century with multicolor lithography; in his 1819 book, he predicted that the process would eventually be perfected and used to reproduce paintings. Multi-color printing was introduced by a new process developed by Godefroy Engelmann (France) in 1837 known as chromolithography. A separate stone was used for each color, and a print went through the press separately for each stone. The main challenge was to keep the images aligned (in register). This method lent itself to images consisting of large areas of flat color, and resulted in the characteristic poster designs of this period.

“Lithography, or printing from soft stone, largely took the place of engraving in the production of English commercial maps after about 1852. It was a quick, cheap process and had been used to print British army maps during the Peninsula War. Most of the commercial maps of the second half of the 19th century were lithographed and unattractive, though accurate enough.”

Materials, Tools and Techniques

Lithographic stone
Every printing process requires a print template, ie a medium containing the texts, drawings and pictures to be printed. For lithographic lithography stone is used. In the trade, lithographic stones in different thicknesses between 5 and 10 cm are offered. The richest deposits are mined in France at Dijon, in Switzerland in Solothurn and in Germany in Solnhofen. Solnhofen slate is considered the world’s best material for lithographic printing plates.

The quality of a lithography brick correlates with its hue. A yellow stone is of inferior quality, because it can absorb a lot of water due to its molecularly open structure and thus does not allow a clean pressure. A gray stone is molecularly denser and therefore provides better print results. Solnhofen Plattenkalk has a gray-blue color. Its consistency is even denser, giving it even better printing properties.

Lithographic stones are ground before use. This process can be done both manually and in a grinding machine. New stones have to be ground flat; already used stones must be freed from the previous printed image. Depending on the intended drawing technique, the stone is sanded smooth, grained or polished.

In order to be used in lithography, the stones must have a predetermined thickness, so they do not break under the pressure of the lithographic press. The required strength is around 8-10 cm; To achieve this, the stone on which the printing surface is located is glued or plastered onto a second of inferior quality. The decisive factor is that the stone is absolutely plane-parallel and has the same strength everywhere. Nevertheless, it happens that the stone breaks during printing.

Lithographic ink and chalk
To manually transfer a drawing to the stone, the lithographer needs a pen and lithographic ink. This ink consists of the basic substances wax, fat, soap and soot. Here, a distinction is made between industrially manufactured liquid ink and so-called rod ink. The rod shower must be rubbed with distilled water for use.

Lithographic chalk comes in the form of pencils and as square chopsticks, which are clamped in a holder. There are six degrees of hardness, with 0 representing the softest and 5 the hardest. Chalk consists of the same substances as lithographic ink. The soft chalk is suitable for dark areas and shadows, while the harder grades are used for fine gradations.

Drawing Instruments
Lithographic shower is transferred to the stone with a steel drawing pen. These are special springs that are softer than standard plumes. If a feather becomes dull from use, it can be sharpened on an Arkansas stone if necessary to create fine lines or spots. Another important tool is the scraper to make corrections like with an eraser on the drawing. The lithographer owns a whole assortment of narrow and broader scrapers, which often have to be resharpened with the help of the oilstone.

Drawing table
If possible, the stone should not be touched by hand, as every fingerprint leaves greasy marks. That’s why the lithographer works on a specially designed lithographic console or table. The industrial chromolithograph worked standing or sitting on a wooden desk. For sitting he had a height-adjustable wooden swivel chair without backrest. The desk was slightly inclined from back to front and the two side walls protruded about 10-12 cm beyond the table top. Over the tabletop a so-called wooden bracer was laid. Underneath lay the lithographic stone, which could now be worked on with the feather or the scraper, without touching it with his hand. Today, artists use similarly designed tables for their lithographic work.

Creation of the printed image
In order to transfer the printed image to the stone, the lithographer has several techniques at his disposal.

Lithographic Techniques
In spring technology, a pen drawing is placed directly on a smooth-cut stone. In general, the lithographer needs a preliminary drawing as a stop. He uses transparent paper to which the contours of the original drawing are transferred. The reverse side of the transparent paper is then rubbed with graphite or red chalk and the paper is positioned and fixed on the stone in the wrong direction. With a steel needle, the lithograph traces the contours and transfers them to the stone so clearly visible. Today, artists project a photo of the subject on an episcopal stone and trace the contours.

The spring technology is one of the oldest processes in lithography. The drawing is reversed with the steel spring or the bourdon tube and lithographic shower on the previously smoothed surface of the stone. Minor corrections are made by the lithographer with the scraper. When the picture is ready and the ink dried, the stone is rubbed off with talcum and then gummed with gum arabic as protection.

To prepare a chalk lithograph, the stone is grained with sand, so it gets a rough surface. For graining, quartz sand was formerly used. Today you take silicon carbide, which is offered in the trade in different grain sizes of coarse, medium and fine. The printed image is transferred to the stone reversed as in the spring technology. The sharpening of the chalk is done from the top with a sharp knife. Depending on the tonal value of the drawing, the lithographer chooses a hard chalk for light areas, but softer chalks for darker areas. Again, minor corrections can be made with the scraper. The chalk lithograph is one of the most expressive techniques in the graphics. For example, wiping with a special wiper, the Estompe, and triturating the chalk coating creates a diminutive effect with smooth transitions. The aftertreatment of the finished drawing is again with talc and gum arabic.

The stone engraving was used especially for business cards, letterheads and securities because of their fine line drawing. For this, the lithographer uses a gray-blue stone of the highest quality, which is first ground and then with clover saltis polished. The poisonous clover salt is a potassium dioxalate and forms a compound with the limestone, in which the pores are closed and the operator produces a mirror-smooth surface by polishing with a tampon. Thereafter, the stone is covered with a dark colored layer of gum arabic. Again, a preliminary drawing is created as a stop before the lithographer scores the drawing with an engraving needle or an engraved diamond. The needle pierces the rubber layer and the lines in the stone surface may be at most 0.2 mm deep. Then the stone with olive oilsoaked before the lithographer removes the rubber layer with water. Although the engraved lines lie deeper in the stone, they can be dyed with a rough leather roller or with a tampon. The absorbent paper must be slightly moistened to better conform to the stone and take on the color.

Creating Halftones
Before the invention of the grid so-called halftones could be generated only with manual techniques. In lithography there are the following possibilities:

In the feather puncturing style, feather and ink are used to place the dots on the stone point by point. The dot density and size depends on the respective tonal value of the original. The most well-known technique in chromolithography is called Berliner Mannier, in which the lithographer applies a semicircle to the dots. The colored lithographs often consisted of twelve or more colors printed on top of each other, which differed greatly in their brightness. Thus, the brighter colors were roughly dotted and the tones were even underlaid. The darker, drawing colors were executed by the best lithographers, who could set very fine points.

The Tangiermanier eventually supplanted the spring stipple partly because it was much easier. Here, a hardened gelatin film already carries the desired pattern of dots, lines or other shapes, which is transferred directly to the stone after being colored by pressing. Spots that should remain free are covered with a repellent layer of gum arabic. However, this technique is only suitable for smooth halftones. Gradients and shades can not be generated with it.

In the spray painting, which was already known Senefelder, a ink-saturated brush is brushed over a sieve, which is held at a certain distance above the stone. Again, the areas covered with gum arabic, on which later no color should adhere. A gradation of the tonal values is generated by the frequency of the injection process.

In the Schabmanier, also called asphalt or Tuschemanier, is applied on a grained stone over the entire surface of an asphalt layer. The light image parts are lightened after drying with a doctor blade, with sandpaper and lithographic needles of the template accordingly. The method is particularly suitable for fine tonal gradations. When the drawing is finished, the stone is treated with a strong caustic solution of gum arabic and seven percent nitric acid.

Preparation of stone for printing
The drawing on the stone can not be printed without preparation. The lithographer and the lithographer call this chemical process etching. The fat-friendly printing areas, ie the drawing, should be reinforced in their capacity and the non-printing parts of the stone should remain fat-repellent and water-absorbent. The etching consists of a mixture of nitric acid, gum arabic and water, which is applied with a sponge on the stone surface and acts. By etching nothing is removed or etched away, but only optimized the printing property of the stone. The process can be repeated several times and is considered complete when the first proofs have been made without any change.

For this activity a lot of experience is necessary in addition to expertise. Artists today have their lithographs partially commissioned by an experienced lithographer so as not to jeopardize the outcome of their work.

Lithography
In the lithography, a distinction is made between the manual press and the rapid press. Today, only a few hand presses are in operation in Germany, where prints are made for artists. The best-known hand press or toggle press was created in 1839 in the workshop of the locksmith Erasmus Sutterin Berlin and is more of a tool than a machine dar. The frame of the hand press is made of heavy cast iron, in which there are a cart or cart and a roller, with which the stone can be manually moved back and forth. The pressing pressure is done by pressing down a grinder, under which the car is pulled through with the stone. The paper to be printed is placed between the stone, previously rolled in with ink, and a firm, smooth cardboard, press cover or pressboardcalled. After removing the press cover, the printed sheet is carefully lifted off and inspected. To set the right friction pressure, the lithographer needs experience and tact. For each hand press, there are different widths of rifers, which are adapted to the respective stone size.

With the further development of lithography in the 19th century and the growing demand for printed matter, the hand press could no longer meet the requirements. This requirement was met by the lithographic press, whose hourly printing output was around 800 sheets. The considerably larger stone was not printed by a grinder, but by a roller. The inking unit ensured a uniform distribution of color on the color table, which was picked up by further ink rollers and transferred to the stone. Dampening rollers took over the necessary moistening of the stone. The car with the stone ran first under the dampening rollers, further under the inking rollers and finally under the impression cylinder. On the cylinder covered with a blanket was the paper, was now printed and stored on the Auslegetisch again. The sheet to be printed was created manually, mostly by women. The drive of the Schnellpresse took place first manually, but later bySteam engines via drive belts.

Unlike the modern four- or six-color presses, this lithographic press was able to print one color at a time. This meant that in a twelve-color lithograph printing had to be repeated twelve times. It is easy to imagine how elaborate color images were produced at that time.

Transfer printing method
The term transfer printing or autography encompasses methods by which drawings or prints are transferred from the paper to the lithographic stone. The transfer printing processes include overprintingin which a drawing of a stone is printed on a special transfer paper and then transferred to a second stone, for example a machine stone. This process is repeated until the much larger machine block of its size contains many drawings. The transfer paper is provided with a water-soluble coating, which forms a separating layer between drawing or printing and paper. It is moistened, placed on a second stone and transferred under pressure. The paper is then moistened again until it can be easily removed. The drawing is now visible in all details on the second stone and can be treated like a normal lithograph.

The machine stone used in the lithographic press generally contained lithographs that were produced by transfer printing. Depending on the number of copies, a certain number of copies or benefits, ie copies of the original lithograph, were produced.

The Abklatsch or gossip was used in chromolithography to provide the number of colors corresponding to many stones with the contours of the printed image. The lithographer previously created a fine-line drawing of the original image, which contained outlines and color differences, and served as a blueprint for later chromolithography. Again, transfer paper was used, but provided only with so little color that the contours of the preliminary drawing later adopted no ink.

Many artists have used the transfer printing paper, alongside Honoré Daumier and Toulouse-Lautrec also Emil Nolde, Ernst Barlach, Henri Matisse and Oskar Kokoschka. However, this technique results in a slight loss of quality in the printed image.

Chromolithography
Already Senefelder dealt with the colored reproduction of fonts, maps and pictures. He underlayed a chalk lithograph with a clay plate, a chamoiston, from which the lights had been removed by means of scraping technique. For the viewer, the impression of a multicolored lithography was created.

In 1837, German-French lithographer Godefroy Engelmann (1788-1839) from Mulhouse patented a colored version of lithography called chromolithography (color lithography, color lithography), which was to remain the most widely used method for high-quality color illustrations until the 1930s, Chromolithographies of up to 16, 21 and even 25 colors were not uncommon. However, it was clear that this was a very time-consuming and costly process. After the introduction of the lithographic printing press around 1871, large quantities of colored lithographic printed matter were produced, since now higher print runs were possible.

As a template or original served the Chromolithografen a painted picture. In the first step, a contour drawing was made on stone. It was a drawing of fine lines, which marked the outlines and color differences of the original. This contours plate served the lithographer as a clue for the exact elaboration of the intended individual colors. Using the transfer printing process, copies of the contour plate called gossip were then made on a number of stones corresponding to the number of colors provided. The clapper showed the contours only hinted at in a bright hue and later disappeared during the preparation of the finished chromolithography print.

After finishing the brighter colors, the proof was started. With the help of thin crosses, which were called pass marks or passport marks, the motif to be printed could be printed over all colors exactly and accurately. This process was called needlesthe proof. Previously, the lithographer had drilled a tiny hole in the middle of the register marks on the right and left of the stone. These holes were repeated on the paper to be printed, which could now be positioned exactly on the stone with the help of two needles. After printing each color, the Chromolithograph examined the progress of its work and then processed the next darker color. Finally, the finished proof was presented to the customer, who was now able to express his requests for change. After the corresponding correction, the job was ready for printing and the edition could be printed in the lithographic press.

Since the machine block was considerably larger than the Andruckstein, depending on the number of copies several Umdrucke were produced by the original lithograph. If the machine block had not yet been filled, additional orders could be placed on the stone. Despite the slight loss of quality, the print run from the machine block should be as close as possible to the result of the proof.

Photolithography
Already the Frenchman Niépce copied 1822 photographic negatives on the litho stone. However, there was no way to resolve the photographic image into printable halftones. As the inventor of glass engraving raster applies Georg Meisenbach, who in 1881 developed the high-precision glass engraving screen and thus could disassemble photographically halftones into printable halftone dots for the first time. This screening was done in a reproduction camerain which the photographic plate to be exposed has been preceded by a grid plate. Because of the differentiated tonal reproduction, this technique allowed for printed reproduction in six or four colors instead of twelve or more, making it far more economical than conventional chromolithography.

To make the necessary separations, the Reprofotograf used color filters. The negatives on glass thus produced were processed by the photolithograph with Farmer’s attenuator to lighten it and blue wedge color to darken it. Non-printing areas were rendered opaque with red chalk or cover red. The finished retouched negatives served as copy templates for the stone copy. A prepared stone was sensitized with a protein chromate solution. This consists of a solution of distilled water, dry protein, ammonia and ammonium bichromatewith which the stone was doused and evenly distributed and dried in a sling. The photolithograph now laid the retouched negative layer on top of the stone and weighted it with a glass plate. The games outside the negative got a black paper cover. In a Steinkopiergerät the exposure took place with carbon arc light, whereby the exposed parts were cured. Subsequently, the stone was rolled in black ink and in a flat, water-filled basin, the copy was developed with a cotton ball. The unexposed parts dissolved and on the stone appeared a positive reversed color separation. This could now be manually edited again, before the stone was prepared for printing.

A similar process was the asphalt copying, in which the stone was sensitized with a solution of asphalt, turpentine, benzene and chloroform. However, this method was extremely hazardous to health.

After the lithography had been replaced by offset printing, only the misleading job title Fotolithograf remained, although this occupation had nothing to do with a lithographic stone. The later correct job title was Druckvorlagenvorbereiter – specializing in offset printing.

Evaluation
The value of a lithograph depends on the number of copies drawn (this determines the rarity), the artist’s rating and the artist’s involvement in the draw.

Modern lithographic process
High-volume lithography is used presently to produce posters, maps, books, newspapers, and packaging—just about any smooth, mass-produced item with print and graphics on it. Most books, indeed all types of high-volume text, are now printed using offset lithography.

For offset lithography, which depends on photographic processes, flexible aluminum, polyester, mylar or paper printing plates are used instead of stone tablets. Modern printing plates have a brushed or roughened texture and are covered with a photosensitive emulsion. A photographic negative of the desired image is placed in contact with the emulsion and the plate is exposed to ultraviolet light. After development, the emulsion shows a reverse of the negative image, which is thus a duplicate of the original (positive) image. The image on the plate emulsion can also be created by direct laser imaging in a CTP (Computer-To-Plate) device known as a platesetter. The positive image is the emulsion that remains after imaging. Non-image portions of the emulsion have traditionally been removed by a chemical process, though in recent times plates have come available that do not require such processing.

The plate is affixed to a cylinder on a printing press. Dampening rollers apply water, which covers the blank portions of the plate but is repelled by the emulsion of the image area. Hydrophobic ink, which is repelled by the water and only adheres to the emulsion of the image area, is then applied by the inking rollers.

If this image were transferred directly to paper, it would create a mirror-type image and the paper would become too wet. Instead, the plate rolls against a cylinder covered with a rubber blanket, which squeezes away the water, picks up the ink and transfers it to the paper with uniform pressure. The paper passes between the blanket cylinder and a counter-pressure or impression cylinder and the image is transferred to the paper. Because the image is first transferred, or offset to the rubber blanket cylinder, this reproduction method is known as offset lithography or offset printing.

Many innovations and technical refinements have been made in printing processes and presses over the years, including the development of presses with multiple units (each containing one printing plate) that can print multi-color images in one pass on both sides of the sheet, and presses that accommodate continuous rolls (webs) of paper, known as web presses. Another innovation was the continuous dampening system first introduced by Dahlgren, instead of the old method (conventional dampening) which is still used on older presses, using rollers covered with molleton (cloth) that absorbs the water. This increased control of the water flow to the plate and allowed for better ink and water balance. Current dampening systems include a “delta effect or vario,” which slows the roller in contact with the plate, thus creating a sweeping movement over the ink image to clean impurities known as “hickies”.

This press is also called an ink pyramid because the ink is transferred through several layers of rollers with different purposes. Fast lithographic ‘web’ printing presses are commonly used in newspaper production.

The advent of desktop publishing made it possible for type and images to be modified easily on personal computers for eventual printing by desktop or commercial presses. The development of digital imagesetters enabled print shops to produce negatives for platemaking directly from digital input, skipping the intermediate step of photographing an actual page layout. The development of the digital platesetter during the late 20th century eliminated film negatives altogether by exposing printing plates directly from digital input, a process known as computer to plate printing.

Microlithography and nanolithography
Microlithography and nanolithography refer specifically to lithographic patterning methods capable of structuring material on a fine scale. Typically, features smaller than 10 micrometers are considered microlithographic, and features smaller than 100 nanometers are considered nanolithographic. Photolithography is one of these methods, often applied to semiconductor device fabrication. Photolithography is also commonly used for fabricating micro electro mechanical systems (MEMS) devices. Photolithography generally uses a pre-fabricated photomask or reticle as a master from which the final pattern is derived.

Although photolithographic technology is the most commercially advanced form of nanolithography, other techniques are also used. Some, for example electron beam lithography, are capable of much greater patterning resolution (sometimes as small as a few nanometers). Electron beam lithography is also important commercially, primarily for its use in the manufacture of photomasks. Electron beam lithography as it is usually practiced is a form of maskless lithography, in that a mask is not required to generate the final pattern. Instead, the final pattern is created directly from a digital representation on a computer, by controlling an electron beam as it scans across a resist-coated substrate. Electron beam lithography has the disadvantage of being much slower than photolithography.

In addition to these commercially well-established techniques, a large number of promising microlithographic and nanolithographic technologies exist or are being developed, including nanoimprint lithography, interference lithography, X-ray lithography, extreme ultraviolet lithography, magnetolithography and scanning probe lithography. Some of these new techniques have been used successfully for small-scale commercial and important research applications. Surface-charge lithography, in fact Plasma desorption mass spectrometry can be directly patterned on polar dielectric crystals via pyroelectric effect, Diffraction lithography.

Lithography as an artistic medium
During the first years of the 19th century, lithography had only a limited effect on printmaking, mainly because technical difficulties remained to be overcome. Germany was the main center of production in this period. Godefroy Engelmann, who moved his press from Mulhouse to Paris in 1816, largely succeeded in resolving the technical problems, and during the 1820s lithography was adopted by artists such as Delacroix and Géricault. After early experiments such as Specimens of Polyautography (1803), which had experimental works by a number of British artists including Benjamin West, Henry Fuseli, James Barry, Thomas Barker of Bath, Thomas Stothard, Henry Richard Greville, Richard Cooper, Henry Singleton, and William Henry Pyne, London also became a center, and some of Géricault’s prints were in fact produced there. Goya in Bordeaux produced his last series of prints by lithography—The Bulls of Bordeaux of 1828. By the mid-century the initial enthusiasm had somewhat diminished in both countries, although the use of lithography was increasingly favored for commercial applications, which included the prints of Daumier, published in newspapers. Rodolphe Bresdin and Jean-François Millet also continued to practice the medium in France, and Adolf Menzel in Germany. In 1862 the publisher Cadart tried to initiate a portfolio of lithographs by various artists, which was not successful but included several prints by Manet. The revival began during the 1870s, especially in France with artists such as Odilon Redon, Henri Fantin-Latour and Degas producing much of their work in this manner. The need for strictly limited editions to maintain the price had now been realized, and the medium became more accepted.

In the 1890s, color lithography gained success in part by the emergence of Jules Chéret, known as the father of the modern poster, whose work went on to inspire a new generation of poster designers and painters, most notably Toulouse-Lautrec, and former student of Chéret, Georges de Feure. By 1900 the medium in both color and monotone was an accepted part of printmaking.

During the 20th century, a group of artists, including Braque, Calder, Chagall, Dufy, Léger, Matisse, Miró, and Picasso, rediscovered the largely undeveloped artform of lithography thanks to the Mourlot Studios, also known as Atelier Mourlot, a Parisian printshop founded in 1852 by the Mourlot family. The Atelier Mourlot originally specialized in the printing of wallpaper; but it was transformed when the founder’s grandson, Fernand Mourlot, invited a number of 20th-century artists to explore the complexities of fine art printing. Mourlot encouraged the painters to work directly on lithographic stones in order to create original artworks that could then be executed under the direction of master printers in small editions. The combination of modern artist and master printer resulted in lithographs that were used as posters to promote the artists’ work.

Grant Wood, George Bellows, Alphonse Mucha, Max Kahn, Pablo Picasso, Eleanor Coen, Jasper Johns, David Hockney, Susan Dorothea White and Robert Rauschenberg are a few of the artists who have produced most of their prints in the medium. M. C. Escher is considered a master of lithography, and many of his prints were created using this process. More than other printmaking techniques, printmakers in lithography still largely depend on access to good printers, and the development of the medium has been greatly influenced by when and where these have been established.

As a special form of lithography, the serilith process is sometimes used. Seriliths are mixed media original prints created in a process in which an artist uses the lithograph and serigraph processes. The separations for both processes are hand-drawn by the artist. The serilith technique is used primarily to create fine art limited print editions.