Authoritytgm012402Scope NoteProcess patented by Henry A. Marchant in 1857 involves an albumen photographic print adhered to a flat piece of glass with a heated mixture of clarified wax, rectified turpentine, and dammar gum. The photograph is then coated with another layer of the mixture, topped with a second piece of glass, and placed in a press until the mixture has solidified, rendering the paper transparent. Pigment is then applied to the back of the glass to color the photograph. The process was not commonly used, possibly because it was so difficult and complicated to produce.
