Identification

Chromogenic Prints

common use: 1941-Present

Dye Stability and Coupler Staining

Image stability has long been the shortcoming of chromogenic prints and has led to characteristic fading in numerous print materials. In addition to dye fading, many chromogenic prints exhibit magenta coupler staining, which produces a yellow stain wherever magenta dye is absent. This is most noticeable in highlight areas, particularly in borders which would otherwise appear white.

Kodacolor print 1950 (click to enlarge) Kodacolor print 1955 (click to enlarge)   Agfacolor print 1978 (click to enlarge) Ektacolor print mid-1970s (click to enlarge)

Kodacolor print 1963 (click to enlarge)   Ansco Printon (click to enlarge)   Ansco Reversal (click to enlarge)

Backprinting

Many chromogenic prints can be identified as such by pairing a manufacturer’s backprint, which signifies the manufacturer of the material, with a knowledge of what materials were being produced by that company; in some cases even the print material is signified in the backprint.

Back Stamps

During processing many photofinishers chose to apply a stamp to the back of prints. This stamp typically indicates who processed the print, but it may also include the print material as well as the date.

Dye Clouds

Chromogenic images are made up of microscopic dye deposits known as dye clouds, which are created in a coupling reaction between oxidized developer and dye couplers. This is the defining characteristic of the process; only chromogenic materials have dye clouds.

Kodak Coupler Non-Incorporated Prints

Kodak introduced chromogenic prints using a Kodachrome-type (coupler non-incorporated) emulsion on a pigmented acetate base in 1941. These prints often exhibit very little dye fade for their time period and can be identified by their differential gloss.