Dufay / Dioptichrome
Description
“In 1907 the French lawyer Louis Dufay (1874-1936) patented a system whose screen pattern was obtained by the combined use of dichromated colloids, greasy printing inks, and imbibition.16 To take a photograph, the screen was mounted in a metallic frame into which a panchromatic plate was inserted before exposure in the camera. The photographic plate was processed individually and returned to the frame for viewing (Fig. 2.11). To form the screens colored pattern, a plate coated with dichromated gelatin was printed through a screen with parallel opaque lines. After a wash to eliminate the dichromate, the plate was immersed in a red dye. The soft gelatin absorbed the color in the parts that were left unexposed under the screen. The plate was then covered with a black greasy ink that did not adhere to the red lines. It was placed in contact with a plain gelatin-coated plate (the receiving plate) that took in the greasy ink and the red dyes, which were transferred by imbibition. The receiving plate was then varnished overall. When both ink and varnish were dry, a solvent was applied to dissolve the greasy ink. The solvent did not affect the varnish, but as the greasy ink was dissolved portions of the varnish coated over it were also removed, leaving the receiving plate with parallel red lines protected by a varnish. A second dichromated gelatin plate was printed through the screen. It was immersed in a blue dye bath, coated with black greasy ink, and applied onto the receiving plate at a right angle to the red lines. After the greasy ink was removed from the receiving plate, a third dichromated gelatin plate saturated with green was applied to its surface. The varnish was then completely removed, leaving a homogeneous screen whose regular pattern consisted of approximately 150 to 200 red, green, and blue elements per square inch (BJP 1918) (Fig. 2.12). First named Diopticolore when it was announced in 1908, the product was launched in spring 1909 under the name Dioptichrome.17 The plates were manufactured by Guilleminot, Boespflug et Compagnie of Paris and marketed by the Société des plaques et produits Dufay. In 1910 a combined screen version of the Dioptichrome was introduced and marketed under the name Dioptichrome-B (Dobrusskin 1998: 65). Around 1912 the method of manufacturing the screen was changed to produce continuous blue lines alternating with rows of lozenge-shaped red and green elements (Fig. 2.13). Although Dioptichrome had good color rendition and was five to six times faster than the Lumière autochrome (Coote 1993: 44), plates were often defective, with small pinholes that produced green stains around each spot (Coe 1978: 60). It remained on the market until the onset of World War I, when the society was dissolved.”
(Pénichon, Sylvie (2013): Twentieth Century Colour Photographs. The Complete Guide to Processes, Identification & Preservation. London, Los Angeles: Thames & Hudson, on pp. 31–33.)
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Pénichon, Sylvie (2013): Twentieth Century Colour Photographs. The Complete Guide to Processes, Identification & Preservation. London, Los Angeles: Thames & Hudson, p. 32.
Secondary Sources
Pénichon, Sylvie (2013): Twentieth Century Colour Photographs. The Complete Guide to Processes, Identification & Preservation. London, Los Angeles: Thames & Hudson, on pp. 31–33. View Quote
