The Platinum/Palladium Printing Process

The two noble metals Platinum (Pt) and Palladium (Pd) when mixed together with iron salts become photosensitive.  As noble metals do not corrode, the Pt/Pd process is the most archival of all the photographic processes. First patented in the mid 1870s, Pt/Pd prints show a long tonal range producing soft grays to browns depending on the temperature of the emulsions used and the ratio of platinum to palladium. The mixing of the metals combined with the hand coating of the emulsion plus the varying time exposed to UV light, ensures that no two prints are alike. 

The emulsion is prepared using a specific ratio of platinum to palladium to iron salts.  The emulsion is hand painted onto a speciality fine art photographic paper and allowed to dry.  A digital photographic negative is prepared using an inkjet printer and printed to the size of the desired final image.  The negative is placed in contact with the dried emulsion and placed into a contact printing frame.  This frame is then placed into a UV exposure unit or can be exposed in direct sunlight.  When a faint ghost of the image starts to appear, the paper is transferred to a developer tray. The developer chemicals are poured quickly over the print and the image is instantly revealed.  The print is then cleared of excess emulsion through several clearing chemical baths and with a final wash in water.  The print is then dried.  The Platinum/Palladium print is a slow methodical photographic printing process from the start to the finish.

The final prints usually show “artist’s marks” - the exposed brush strokes from the emulsion outside of the final image.  These brush strokes may be displayed in the final framing of the image or may be covered by a mat board, revealing only the edges of the print.