In addition to the above techniques, I have also been making my own Platinum Palladium prints for a year now. Platinum Palladium printing is a traditional photographic printmaking technique dating back to a period in photographic history that predates silver gelatin prints. To create a print, I start by hand coating platinum palladium emulsion onto a cotton rag paper using a special glass rod. The Platinum-Palladium mixture is sensitive to ultraviolet light and the process requires a contact print; the negative must be the same size as the desired print. During the development part of the process, the Platinum and Palladium becomes embedded within the fibers of the paper, which results in an image that is as permanent as the paper itself. The final color tonality can range from warm black, to reddish brown, with a range of grays in the midtones. After the development under UV light, the prints have to be washed for 1.5 hours per print."
Margaret Lansink