Dufaycolor: materials, techniques and deterioration

Abstract

This paper investigates the materials and techniques of the additive colour screen process known as Dufaycolor. The focus of the paper is on Dufaycolor as used in still photography, with only brief mention of its use in cinematography. Included is a description of the general principles of additive colour processes; a brief comparison of the Autochrome and Paget processes with Dufaycolor; a history of Louis Dufay’s processes, culminating in Dufaycolor; the technical composition of Dufaycolor transparencies; manufacturing techniques; and how the photographic image was formed and viewed. Transparency types and sizes are also described. In addition, the paper provides a visual description of a number of Dufaycolor transparencies held in Australian collections, giving characteristics that can aid in the identification of this unusual photographic process. This description includes a brief discussion of possible causes of deterioration. Information was sourced from literature and an inspection of original materials from three Sydney cultural institutions: the Lucy Osburn–Nightingale Museum at the Sydney Hospital, the State Library of NSW and University of Sydney Macleay Museum.

Keywords:

• Dufaycolor
• additive colour screen process
• cellulose acetate
• collodion
• réseau
• silver gelatin