The Platinum-Palladium Process
The Negative
The platinum process, like many of those alternative processes from the late 19th and early 20th centuries, requires a negative the same size as the final image. These large negatives are output using an inkjet film and printer.
Measuring the Sensitiser
The sensitiser is made up of several solutions, measured by drops.
Coating the Paper
The platinum print is made by hand-coating a sheet of paper, by brush, with light sensitive chemicals containing platinum and palladium metal solutions.
The ratio of the two metals can be slightly adjusted to control the colour of the image – a higher proportion of platinum will result in a cooler image, while more palladium will give a warmer.
Developing the Print
Once the sensitised paper is dry, the negative is registered on top, placed in a vacuum frame to ensure complete contact and exposed to ultraviolet light.
After exposure the negative is removed from the paper and the print placed in the potassium oxalate developer where the image appears instantaneously. The print is rinsed, placed in several successive clearing baths to remove unwanted chemicals and metals and finally washed and dried.
Drying the Print
After developing the print, it’s placed in several clearing baths to remove unwanted chemicals and metals, washed, and hung up to dry.