Imaging the Surface of a Hand-Colored 19th Century Daguerreotype.

Daguerreotypes are valued artifacts that constitute a unique historical photographic memory of the 19th century. Understanding their surface chemistry is important in order to conserve and, when necessary, to restore them. Colored highlights were often added by hand to emphasize different features on the daguerreotype's subjects. In the present work, we report on a daguerreotype that was hand-colored with a red pigment that was added to the cheeks of the two individuals. A series of experiments using micro-Raman and micro-Fourier transform infrared spectroscopy and synchrotron-based X-ray fluorescence microscopy and absorption spectroscopy are used to analyze the surface and to determine the nature of the pigment used as well as the common elements present in the fabrication of the daguerreotypes.