The Flexichrome: visual examination and scientific analysis of an overlooked color process.

Abstract

The recent display at the Art Institute of Chicago of a color photograph by Herbert Lyman Emerson (Untitled, c.1950) prompted in-depth research into the photographic process used to create it. Prior to its acquisition, the print had been identified as a hand-colored gelatin silver print. Due to the vibrancy of colors and overall appearance, however, it was suspected that it could instead be a carbro print, overpainted for commercial printing purposes. Non-invasive XRF analysis confirmed the absence of silver, consistent with the carbro process, but a more detailed visual examination did not reveal evidence for the superimposed color layers characteristic of this process, and suggested that it could be instead a Flexichrome. This finding led to further material research into the Flexichrome process. The Crawford Flexichrome process was first developed and marketed by Jack Crawford in the early 1940s. Kodak purchased the patent from Crawford and remarketed the product as the Kodak Flexichrome from the late 1940s until the early 1960s. This paper presents an overview of the Flexichrome process and, through the study of the Art Institute’s photograph alongside selected Flexichrome reference prints and historic Flexichrome dyes, investigates the technology and variations in the formulations available. Prints and dye samples were characterized using a complement of analytical techniques including visible and fluorescence light microscopy, Fourier transform infrared spectroscopy, and x-ray fluorescence spectroscopy. A key goal of the study is to establish identification clues for Flexichromes, informed by results from invasive and non-invasive analytical techniques.