photography since the 1960s. Even so, prints made
through this process do fade relatively rapidly
when exposed to light.
Polaroid is one of the most fascinating printing
processes. Invented by Dr. Edwin Land and mar-
keted since 1948, it can produce almost instant
prints directly from the camera, first only for
black and white and later in 1963 in color. An
extremely sophisticated multilayer emulsion, it is
based on the diffusion of silver or colorants through
the layers, this shift being stopped proportionally to
the quantity of light received in each area, thus
providing a direct positive. Although its main use
has been in amateur and scientific photography,
several artists have chosen it as their favorite photo-
graphic media, notably Lucas Samaras and Rosa-
mund Purcell. The identification of these prints is
easy in their small format (up to 810 inches), as
they have white margins (three being the same size
and a larger one that contained the chemicals used
in the development). The larger formats are recog-
nizable through the chemical streaks that appear in
the margins from the development process. The
dark storage stability of Polaroid color is adequate
but they can develop overall yellow stains and
cracks in the emulsion.
Polaroid emulsion can be transferred to drawing
paper or other surfaces. Polacolor ER films can be
transferred directly by pressing the negative on the
desired surface, while it is still developing, or from
the fully developed positive, by peeling off the
emulsion submerging it in hot water, and then pla-
cing it over another support, allowing creative
manipulations by stretching and sculpting it. The
SX-70 Polaroid also has had wide artistic accep-
tance because the image can be manipulated, while
developing, by pressing or rubbing with spatulas or
other tools.
In the 1990s, new ways of digitally producing
photographic quality prints have been introduced
at a rapid rate, however, they can be grouped into
four major groups of printer devices: inkjet, dye-
sublimation, laser prints, and photographic paper
printers. The latter is basically a computer con-
trolled professional enlarging system, only that
instead of exposing all the paper at once, the
exposition is done sequentially creating line after
line of dots with a laser beam, and all kinds of
color or monochromatic photographic papers can
be used.
Inkjet printers deliver extremely fine drops of ink
on the paper, allowing the use of a great variety of
surfaces and materials. The colors in the print are
formed by adjacent drops of ink, that show a pixe-
lated structure when seen with magnification. The
number of inks used varies but usually include
black and three to five colors. The first inks had
poor stability, only two to five years. Since then the
quality of the inks have improved, and some have
been tested to provide more than 100 years of dark
stability. Obviously, another important factor to
consider is the quality of the paper itself. Intro-
duced in the early 1990s it is probably the most
popular way of printing digital images, as the prin-
ters are very affordable for the quality they render
and among artists the professional Iris printers
offer a wide range of choices.
Dye-sublimation printers are based on wax-
based primary color inks that are sent as a liquid
to the paper, where they mix to form the full spec-
trum of colors. They provide a continuous tone
under magnification. Laser color printers are
based on same principles as monochromatic ones,
and can give excellent results but as with dye-sub-
limation the choice of papers is limited and the
costs higher.
The digital revolution has made it possible to
practice photography without a darkroom. Some
people mourn the loss of the magical moment when
the image appears in the developing tray, but
others consider it a liberation from the inconveni-
ence of working in darkness and hazards of the
chemicals involved. The turn of the twentieth to
the twenty-first century presents an uncannily simi-
lar situation to that which occurred at the previous
turn of the century, when both artisan and indus-
trial processes enriched the possibilities of photo-
graphic printing. Now we face a world where
chemical and digital photography again offer
photographers a wide spectrum of possibilities as
to how a photograph is printed.
ManuelSantos
Seealso:Conservation; Darkroom; Digital Photo-
graphy; Dye Transfer; Film; Instant Photography;
Non-Silver Processes; Pictorialism; Polaroid Cor-
poration; ToningFurther Reading
Baldwin, Gordon.Looking at Photographs: A Guide to Tech-
nical Terms. Los Angeles: J. Paul Getty Museum, 1991.
Coe, Brian, and Mark Haworth-Booth.Guide to Early
Photographic Processes. London: Victoria and Albert
Museum, 1983; American edition: New York: Antique
Collectors Club, 1984.
Nadeau, Luis.Encyclopedia of Printing, Photographic and
Photomechanical Processes. 2 vols., Fredericton, New
Brunswick: Atelier Luis Nadeau, 1989.
Reilly, Jim.Care and Identification of Nineteenth Century
Photographic Prints. Rochester, NY: Kodak, 1986.PRINT PROCESSES