Investigation and analysis of vintage hand-colored photographs from francis amin's private collection, Egypt

Prior to the introduction of color photographic process, the only method of producing photographs in color was to apply coloring agents by hand. Hand-colored photographs were very popular in the 1920s and they are still produced today. However, little research has been carried out to study the coloring agents used in terms of their chemical composition and how they respond to deterioration agents (i.e., temperature, relative humidity and UV radiation). The identification of pigments on hand-colored photographs is necessary to profoundly understand the material and technique used, and thus select proper conservation procedures. In many cases, the application of non-invasive techniques is mandatory since physical sampling of the art works is not possible. This study represents a research aimed at studying the hand-colored photographs and the identification of the pigments. For this purpose, X-ray fluorescence spectroscopy is used in detecting elements that make up the photograph and most significantly the pigments used for hand-coloring. The paper further discusses the use of multispectral imaging system as a new approach in photograph conservation field. While this technique does not provide the analytical capability that spectroscopies offer, its use has the advantage of being a rapid solution for the examination of large areas. The paper looks into another important issue of conservation which is the impact of different degradation agents on the color of the photographs. This is particularly necessary for such photographic materials since they are very sensitive to the surrounding environment. For evaluating the effect of the principal degradation agents, a group of photos was exposed to different artificial aging conditions (i.e. temperature, relative humidity and UVA). The CIELAB color coordinates (L*, a*, b*) were used to express color change.