June 2, 2010
Press Articles :: Palladium Printing
The Palladium Printing Process dates back to the mid 1800's and is one of the only truly archival photographic processes.
In the Palladium Process, fine art paper is sensitized with a mixture of ferric oxalate, potassium chlorate(which increases contrast)and sodium chloropalladite(palladium and salt).The sensitizing is accomplished by pouring the sensitized solution (emulsion) onto the paper and then brushing it on evenly with a fine brush. Depending on the desired look and depth of the final print you may use one or two coatings of the emulsion.
After drying the print is exposed in direct contact to the negative by either sunlight or a strong ultraviolet light source and may be developed in a variety of chemicals, depending upon the desired warmth of the final print. I use a saturated solution of potassium oxalate heated to approximately 120 degrees to give a great deal of warmth to the image.
When the ferric salts are exposed to light they are reduced to the ferrous state. When the print is placed in the developing solution the new ferrous salts are dissolved and reduce the Palladium, in contact with them, to the metallic state. The print is then cleared in hydrochloric acid or various other citric acids to eliminate the remaining ferric salts in the paper. The image that is left consists of metallic Palladium in a finely divided state. The print is then washed for 30 minutes and air dried.
Other than the obvious beauty of the process and the truly archival quality what intrigues me is that each print is different. Within a limited edition each image will have it's own subtleties that make it a truly unique print.
