Hannavy_RT72353_C000v1.indd

(Wang) #1

1117


Gernsheim, Helmut, and Alison Gernsheim, The History of
Photography from the Camera Obscura to the Beginning of
the Modern Era, New York: McGraw-Hill, 1969.
Goldberg, Vicki (ed.), Photography in Print, Writings from 1816
to the Present, New York: Simon and Schuster, 1981.
History of Photography, 1997, t. 21, no. 2, “Why Historiogra-
phy?”
Marien, Mary Warner, Photography and its Critics : A Cul-
tural History, 1839–1900, Cambridge: Cambridge University
Press, 1997.
Newhall, Beaumont (ed.), Photography : Essays and Images,
New York: The Museum of Modern Art, 1980.
——, Beaumont, The History of Photography, 5th ed., New York:
The Museum of Modern Art, 1982.
Rosenblum, Naomi, A World History of Photography , 3r ed.,New
York: Abbeville Press, 1997.
Taft, Robert, Photography and the American Scene: A Social
History 1839–1889 (1938), repr. New York: Dover, 1964.
Wells, Liz, ed., Photography: a Critical Introduction, 3rd ed.,
London: Routledge, 2004.


PHOTOLITHOGRAPHY
Photolithography is a photomechanical printing process
that combines lithography with photography. Through-
out its history, photolithography has included a variety
of forms and printed image effects. Today, it is used in
the printing of everything from magazines to soup can
labels.
Lithography Lithography was invented in 1798 by a
German author, Aloys Senefelder, who was looking for a
practical way to publish his plays. Lithography is based
on the principle that water and grease do not mix. The
traditional lithographic process is as follows: On a fl at
printing surface marks are made in a greasy medium.
The surface is dampened with water, which settles only
on the unmarked areas, as it is repelled by the greasy
drawing medium. Next, a roller covered with greasy
printing ink is rolled over the surface. The ink adheres
only to the drawn marks, the water repelling it from
the rest of the surface. Finally, the ink is transferred to
a sheet of paper by running the paper and the printing
surface together through a special press.
From the beginning artists were intrigued with li-
thography, as they could draw and paint directly onto
the printing plate. Many famous artists, including Pablo
Picasso, Marc Chagall and Andy Warhol, have used
this process. In the early 19th century lithography was
usually monotone and not favored for commercial pur-
poses. Stones were used as the printing surface, which
was a cumbersome and expensive method. By the 1850s
stones were replaced with metal plates— fi rst zinc,
then copper in the 1890s. After the American Civil War
mass production of lithographs was possible. However,
it wasn’t until after the 1876 Centennial Exhibition in
Philadelphia, where it received great exposure, that
lithography fl ourished.
The fi rst photolithographs As early as the 1850s,


attempts were made to create lithographic printing sur-
faces by means of photography. While the ultimate goal
was to create photographically realistic images, the fi rst
photolithographs could only create lines. These prints
are often called line photolithographs. In this process,
a document, such as a pen and ink sketch or hand writ-
ten document, was photographed. The negative that
was produced was used to expose a photographically
sensitive sheet. The lines of the image would harden
and the image was transferred to the printing stone or
metal plate for printing. Transferring the image this way
from a paper sheet, as opposed to drawing the image
directly onto printing stone or plate, is called transfer
lithography. From the 1860s, line photolithography was
used to reproduce engravings, maps, architectural draw-
ings and similar documents. In many early examples,
it is diffi cult to near impossible to determine if such a
lithograph was a photolithograph or a manual (by hand)
lithograph.
While line photolithography was useful, there was
strong desire to add tone and similar detail to the print.
The earliest commercially viable technique that could
create tone was the ink-photo, developed by a London
fi rm, Sprague and Co., in the early 1880s. This was a
transfer lithograph using the reticulation of gelatin to
break up the photographic image into dots and squiggles.
Once the image was photographically transferred on the
gelatin surface, it was transferred to the printing stone
or zinc plate and printed. This process is closely related
to the collotype. The ink-photo was easier and cheaper
to mass produce than the collotype, but the image was
inferior. “Inc-Photo” and the company name is often
printed is often printed on these prints. The ink-photo
processes was used to illustrated many books.
Halftone photolithography With the introduction of the
half-tone process, commercial printers could fi rst make
photolithographic prints with near photographic detail.
Halftone is a photomechanical process that is applied to
numerous printing processes, including relief (the com-
mon method of printing for 19th century publications),
intaglio and lithography. It is often referred to as the
screen process or dot process. With the use of special
screens or glass with cross-hatched lines that break up
the image, the halftone process translates the tones and
detail of a photographic image into a printed pattern of
tiny dots. Under magnifi cation these dots are obvious,
but from normal view they meld into what appears to
be photographic tone. Typically, in the darker areas of
the print, the dots are larger and closer together. In the
lighter areas, the dots will be smaller and further apart.
Examination of the photographically realistic image
in a modern newspaper or magazine will reveal the
halftone dots.
The halftone process was quickly applied to com-
mercial relief printing, with half-tone prints commonly

PHOTOLITHOGRAPHY

Free download pdf