Chromogenic Prints

Assignment 1: Historical Processes: Chromogenic Prints 

Kate Moss Swim Tulum 1994 by Enrique Badulescu [5]

Process:

“A photographic color process that uses three silver images on a single support to create corresponding dye images in the subtractive primary colors. The three superimposed dye images yield a full-color image. Both films and prints are produced using this process.” [2]

·         Dye coupling processes are chromogenic; that is, the color is created during processing. [3]

·         Magenta, cyan and yellow are separated automatically in the three layers of red-, green- and blue- sensitive emulsion stacked on top of one another on the film or paper support. [3]

·         Color intensity is proportional to the density of the silver image. [3]

·         Once the color image is formed, the silver is bleached away, and only the dyes remain. [3]

  

Creation:

Early 20^th century discoveries led to the advent of dye coupling and the widespread production of chromogenic prints:

·         1905: Hinricus Luppo-Cramer shows that brown-colored images are made not of silver but of organic dyes formed during development [3]

·         1907: Benno Homolka establishes coupler development, but successfully produces only blue images [3]

·         1912: two chemists in Berlin, Fischer and Siegrist, patent the application of Homolka’s discovery, which describes the structure and chemistry of most modern color materials. They also describe the integral “tripack” made by coating three emulsions sensitive to green, blue, or red on top of one another.  However, the dyes wandered between the layers and the tripack was not successful. [3]

·         1920s: Leopold Godowsky Jr. and Leopold Mannes experiment constantly, and produce a color image with a tripack. [3]

·         1930: Charles Edward Kenneth Mees, director of research at Kodak, invites Godowsky and Mannes to join Kodak Research Laboratory in Rochester, NY. The result was Kodachrome, a tripack with five layers on a single support. [3]

Associated Uses:

·         16mm Kodachrone film first used in motion pictures in 1935 [3]

·         35mm Kodachrome available for still photography in 1936 [3]

·         processing has 28 stages and lasted 3.5 hours, done exclusively at Kodak in Rochester; becomes only 18 stages in 1938 [3]

·         faster and brighter than all other color films available [3]

·         Americans not used to “miniature” cameras, 35mm takes time to catch on [3]

·         in 1939 Ready-Mount Service introduced, in which film retuned in 2x2 mounts, ready to be projected as slides [3]

·         sale of small slide projectors, ready-made metal frames and modestly priced cameras leads to increased use of color cameras [3]

·         1950s independent photofinishers begin processing film [3]

·         originally chromogenic prints are only offered with a glossy finish, by the late 1960s matte and luster finishes are introduced [3]

·         1977 first minilab installed in the US (small photofinishing unit where processing and printing done in about one hour) [3]

·         Kodachrome discontinued in 2009 [3]

·         chromogenic prints manipulated digitally since the early 1990s

-           device called a film recorder could enlarge prints and make transparencies

-          By the end of the 20^th century a printer existed that could expose color photographic paper directly with lasers driven by a computer file, though it cost about a quarter million dollars. [2] 

Identification Tips:

·         prints from 1941-1981 have a smooth glossy surface and often exhibit slight yellowing of the white-pigmented base. [3]

·         print size varies from 2 ¼ inch x 3 ¼ inch to 8 x 11 inches; many are mounted. [3]

·         prints stamped on reverse with “Kodak”, “Kodachrome”, or both. [3]

·         all print enlargements from 1942-1974 have a stamp on the back that reads “This is a Kodacolor Print made by the Eastman Kodak Company” with the processing date. [3]

·         starting in the 1950s, because Kodak in Rochester was no longer the only processor of film, prints may have a different stamp on the verso. [3]

·         in the 1960s stamping was abandoned entirely and replaced with photographically printing the processing month and year into the margin of the print; in 1961 light grey diagonal lines reading “A Kodak Print” were introduced to the backs of its photographic paper onto which prints were processed. [3]

·         under a loup or stereo microscope, the image appears sharp and made up of minute dots of dye deposits (dye clouds); paper fibers are not visible [3]

Example of dye clouds of a Kodak Royal print under 500x magnification [4]

Preservation Concerns

• appear to be less sensitive to pollutants than black and white photographs [1]

• early generations of prints particularly unstable; 1980s onward more durable [1]

• light can induce fading of dye over time; prints can also fade when stored in dark [1]

• dye fading is accompanied by a shift in the color balance

-          the three colors do not fade at the same rate, which creates an imbalance; when the cyan dye fades, a print appears too red [1]

•   highlight staining: prints acquire a yellow stain particularly visible in the highlight areas [1], specifically in borders which would otherwise appear white [4].

-           result of residual couplers (molecules that initiate dye formation) forming colors as they decompose [1]

-          magenta dye coupler particularly responsible for this phenomenon [1]

• curling of the print, which can be avoided by adding a layer of gelatin to the back of the film to counteract the stress of the layer on the image side [1]

• cracking is induced by light and usually covers the entire print [3]

 

Kodacolor print 1955, exhibiting color fading [4]

Storage Tips:                                

•  light exposure, especially of early prints, should be kept to a minimum                                 

• light exposure should not exceed 12,000 lux-hours (1,112 foot-candle-hours) per year, with a max illumination of 50 lux [3]

• even if never exposed to light, dye coupling materials will deteriorate in the dark

-          rate of deterioration varies according to the chemical structure of the dye, but is inherent to the material

-          rate is a function of temperature and, to a lesser degree, relative humidity [3]

•  materials are best stored at low temperatures and low relative humidity

-          ISO recommends 27 degrees Fahrenheit at 50% RH, and 36 degrees Fahrenheit at 40% RH maximum.

-          RH above 60% can promote fungus growth, and below 15% can result in excessive brittleness of the material [3]

•  paper and mat board enclosures may include buffering, as opposed to old standards which approved nonbuffered enclosures only [3]

   Bibliography

[1] Lavedrine, Bertrand. A Guide to the Preventative Conservation of Photograph Collections. Los Angeles: Getty Conservation Institute, 2003.

[2] Benson, Richard. The Printed Picture. New York : Museum of Modern Art, 2008.

[3] Penichon, Sylvie. Twentieth Century Color Photographs: identification and care. Los Angeles: Getty Conservation Institute, 2013.

 [4] Graphic Atlas. “Idenitification: Chomogenic Prints.”

http://www.graphicsatlas.org/identification/?process_id=48. Accessed 22 September 2015.

[5] Badulescu, Enrique. “Kate Moss Swim Tulum”. 1994. Chromogenic print.

http://www.independent.co.uk/arts-entertainment/art/news/in-pictures-christies-auction-works-featuring-kate-moss-8798574.html?action=gallery&ino=12. Accessed 22 September 2015.