Photographic Processes

Silver Gelatin Process

This contemporary printing process produces beautiful, rich prints made from bright luminous whites, deep blacks, and a full compliment of tones in between. The silver gelatin process was the dominant black and white photographic process of the 20th century.

This process has remained largely unchanged since it was introduced in the 1880s. The fiber paper is coated with gelatin that holds light-sensitive halide particles. The image from a negative is projected onto the paper, exposing the silver particles to varying degrees of light. The paper is then placed in a chemical developing solution where the exposed silver particles are transformed into tones of grey corresponding to the amount of light received by each particle. The wide spectrum of grey tones produced ranges from full black to full white and creates what is called the 'black and white' print.

Platinum Printing Process

Imogen Cunningham became a skilled platinum printer while studying photography in Dresden at the Techniiche Hochschule from 1909 to 1910. In the spring of her year abroad, she wrote her thesis on platinum printing. Introduced in the 1870s, platinum printing is a process that is still practiced today as a handmade photographic process; one which is distinguished by its matte suface and subtle tonal gradations.

The luminous and dimensional appearance is the result of hand-made emulsions of platinum, and often palladium, laid down on archival paper. Platinum, like gold and silver, is a ‘noble’ metal, and the resulting platinum print is stable and permanent. Correctly processed, platinum prints are one of the most archival of any image made on paper. The platinum image is made as a contact print. The negative is placed in direct contact with the platinum-sensitized paper, then exposed to a strong ultraviolet light. The ultraviolet light reduces the platinum to a darker, pure metallic state. The final image is formed out of crystals of pure platinum metals, embedded in the paper fiber.