FRESSON QUADRICHROMY PRINT
The Fresson colour pigment print is inherited from the monochrome carbon "satin paper" process perfected at the end of the nineteenth century by Théodore-Henri Fresson. It was developed by his son Pierre from 1951 and finalised in 1959. It is still one of the techniques offered by the family run Atelier Fresson in Savigny-sur-Orge, France.
This process consists of four layers of bichromated gelatine containing natural or synthetic pigments for cyan, yellow, magenta and black colours, successively applied to the paper support. This is a direct pigment process, i.e. one that does not transfer picture layers onto a receiver media. Although the secrecy surrounding the making of a Fresson quadrichromy print remains, the main steps in the production process have been described by the family workshop. The paper support is put through four successive coating-sensitising-exposure-development phases, one per colour. Sensitising is achieved by dipping the paper in a potassium bichromate solution. During the exposures, each coloured image is obtained by negative enlargement with a corresponding selection filter (for the blue, green or red selection negative). Under the action of the light, the bichromated colloid becomes insoluble. During development, the areas not exposed are eliminated by solubilising in hot water. After every cycle, gelatine is applied to the pigmented layer. Then the print is washed to remove any residual trace of bichromate, then dried in the open air and in a heated press. Retouching may be done before applying a finish, protective gelatine coat.
The Fresson process produces results similar to those of gum bichromate techniques. The paper used has a maximum size of 62 × 92 cm, with a smooth surface, and the final image is matte with saturated colours.
Prints are known for their good light stability, explaining the preference shown by professional photographers during the 1970s and 1980s for this process rather than chromogenic prints.
The alterations seen are essentially mechanical ones, depending on weather conditions during storage and handling, which when poor may cause abrasions or cracks affecting the layers.