Photographic Processes: 1839 – 1889
NON-SILVER PHOTOGRAPHIC PROCESSES
PLATINUM PRINT (platinotype), 1880-1930
Iron-based paper positive with platinum as the final image material
Paper is brushed with a mixed solution of iron and platinum compounds and exposed to light through direct contact with a negative, resulting in a faint image. The image is then developed in a solution of potassium oxalate, causing the image to become fully pronounced. A subsequent hydrochloric acid solution was often used to clear the iron compound left in the paper, which was then washed in water. If the iron compound and/or the hydrochloric acid are not removed completely, the paper will discolor and become brittle over time.
A platinum print has a cool black/grey image tone. The platinum image is extremely stable and shows no signs of fading even after the paper support becomes yellow and brittle.
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Burt Green Wilder Collection. Platinum Print, late 1880s. [zoom] 7 1/8 x 5 3/8 in. Photography gave science a new way to record specimens. Burt Green Wilder (1841-1925) was a comparative anatomist and professor at Cornell University from 1867 to 1910. This platinum print shows a cross-section of a human brain, one of over 600 specimens in Wilder’s collection, to which his own brain was added after his death. |