Lithography is a method of printing originally based on the principle that oil and water
do not mix. Printing is from a stone 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 which 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 aluminum plate. The image can be printed directly from
the plate, or it can be offset, by transferring the image onto a flexible sheet for printing
and publication. As a printing technology, lithography is different
from intaglio printing, 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 word lithography also denotes photolithography, a microfabrication technique used in the microelectronics
industry to make integrated circuits and microelectromechanical systems.
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 substance,
while the negative image would be water-retaining. 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.
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 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 avoided 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 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 HNO
3 is applied to the stone. The function of this solution is to create a hydrophilic layer
of calcium nitrate salt, Ca(NO 3)
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 which 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 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. 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." 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 image. The image on the plate emulsion can
also be created by direct laser imaging in a CTP 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
which 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 that can print
multi-color images in one pass on both sides of the sheet, and presses that accommodate
continuous rolls of paper, known as web presses. Another innovation was the continuous dampening
system first introduced by Dahlgren instead of the old method which is still used on older
presses, which are rollers covered with molleton which 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".
The process of lithography printing is illustrated by this simplified diagram. This press is
also called an ink pyramid due to the fact that 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 manufacturing of microchips. Photolithography is also commonly used for
fabricating Microelectromechanical systems 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. 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. 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 became popular with French artists, Toulouse-Lautrec most
notably of all, and by 1900 the medium in both color and monotone was an accepted part
of printmaking, although France and the US have used it more than other countries.
During the 20th century, a group of artists, including Braque, Calder, Chagall, Dufy, Léger,
Matisse, Miró, and Picasso, rediscovered the largely undeveloped art form 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
which 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.
Gallery
See also Block printing
Color printing Etching
Flexography German inventors and discoverers
History of graphic design Letterpress printing
Lineography Lithography using MeV ions – Proton beam
writing Photochrom
Theodore Regensteiner inventor of the four-color lithographic press
Rotogravure Seriolithograph
Stencil lithography Stereolithography
Typography References
External links Twyman, Michael. Early Lithographed Books.
Pinner, Middlesex: Private Libraries Association, 1990
Lithography and other printmaking definitions Museum of Modern Art information on printing
techniques and examples of prints The Invention of Lithography, Aloys Senefelder,(a
searchable facsimile at the University of Georgia Libraries; DjVu and layered PDF format)
Theo De Smedt's website, author of "What's lithography"
Extensive information on Honoré Daumier and his life and work, including his entire output
of lithographs Digital work catalog to 4000 lithographs and
1000 wood engravings Detailed examination of the processes involved
in the creation of a typical scholarly lithographic illustration in the 19th century
Nederlands Steendrukmuseum Delacroix's Faust lithographs at the Davison
Art Center, Wesleyan University A brief historic overview of Lithography.
University of Delaware Library. Includes citations for 19th century books using early lithographic
illustrations. Philadelphia on Stone: The First Fifty Years
of Commercial Lithography in Philadelphia. Library Company of Philadelphia. Provides
an historic overview of the commercial trade in Philadelphia and links to a biographical
dictionary of over 500 Philadelphia lithographers and catalog of more than 1300 lithographs
documenting Philadelphia. Swiss Cities
Prints & People: A Social History of Printed Pictures, an exhibition catalog from The Metropolitan
Museum of Art, which contains material on lithography