Study of Toned Photographs of the Late 19th and Early 20th Century Using Multispectral Imaging and SEM/EDS Analysis

Abstract Toned photographs became popular in the second half of the 19th and early 20th century, either as stand-alone photographic images or as part of representative cards such as cabinet cards or cartes de visite. Still, further research is desirable to deepen our understanding about materials and techniques that had been used to create toned photographs. This study focusses on toning processes and is based on the analysis of 16 historical photographs from that period. To understand the toning process, information was collected from historical literature, while multispectral techniques and SEM/EDS analysis were applied to the sixteen photographs. Multispectral techniques, both macroscopic and microscopic, provide valuable information on surface and texture, damage phenomena and the photograph’s stratigraphy. SEM/EDS analysis yields information on the elements found in the studied photographs and their stratigraphy. This combination of the evaluation of historical written sources and scientific analysis provided an insight into the materials and techniques used in the toning of photographs.