Characterization of a Fresson four-color prints’ binder components
This work was performed during our second year of study at the Inp (National Institute of Heritage, Paris, France). It is dedicated to the binder of Fresson four-color prints, a pigment printing technique invented by Pierre and Michel Fresson in 1952. This technique is based on the insolubilization in water of dichromate colloid after its exposure to light. If the nature of colloids used in historic pigment processes is well known, the components of the Fresson binder are still a trade secret. These four-color prints being significantly present in heritage collections, they can be subject to conservation treatments. The goal of this study was to identify the colloid nature. In this purpose, chemical tests on punctual samples and cross sections have been realized on a Fresson print sample.