In progress: Seeking additional comments and images to develop this section
Photographic Materials Conservation Catalog
Date: Initiated January 2012
Contributors: Amy Brost, Luisa Casella, Saori Kawasumi Lewis, Stephanie Watkins
The Photographic Materials Conservation Catalog is created and maintained by the Photographic Materials Group of the American Institute for Conservation for the convenience of the membership. The treatments, methods, or techniques described herein are provided for informational purposes. The reader assumes responsibility for any application results or interpretation of information.
Platinum (also called Platinotype) and Palladium
Invented: 1844, Roger Hunt; 1913 Silver-Platinum (Satista), 1917 Palladiotype paper
Patented: 1873, William Willis; 1879, Alfred Clements
Historic Practitioners: Manuel Alvarez Bravo, Alvin Langdon Coburn, Imogen Cunningham, Edward S. Curtis, Peter Henry Emerson, Frederick H. Evans, Laura Gilpin, Frederick Hollyer, Alfred Horsley-Hinton, Gertrude Kasebier, Irving Penn, Edward Steichen, Alfred Stiegliz, Paul Strand, Edward Weston, Clarence H. White
Contemporary Practitioners: Elizabeth Allen, Dick Arenz, Martin Axon (printer), Lois Conner, Jill Enfiled, Chuch Henningsen (printer), Sal Lopez (printer), Pradip Malde, Michael Massaia, Isabel Munoz, Joan Myers, Ted Preuss, Robert Vano, Mike Ware
Image layer: Image layer is imbedded within top fiber structure of the support.
Color: Platinum produces a matte, deep, rich, yet warm, black print. Palladium also produces a matte, rich, deep, but warmer, yellower brown tone. Mixed, the color can be modulated to shades in between (mixture not commonly employed by historic practitioners). Mercury development can also lead to warmer tones. Both metals provide a wider scale of gray tones and less contrast than silver, revered for the nuances and subtleties in the prints. Use of gelatin as sizing, oxidizing chemicals, mercury development (sometimes called "toning"), or more acidic processing produces browner tones. PH, amount of relative humidity, and processing temperature can also modulate final image color. For example, the higher the pH, the lighter the print and conversely, the lower the pH, the darker the print. The color of platinum and palladium prints can also be altered through the addition of toning during processing. The perceived color of the print is also dependent on the color of the paper support.
Support: Most often paper, sized with gelatin, arrowroot, and starch.
Analysis: Detectible by X-Ray Fluorescence (XRF); platinum, palladium, iron, sometimes silver. Mercury, lead, uranium (from toning).
Image "burn": Sometimes, image material in a platinum print darkens the paper support and it may be visible from verso. Similarly, when a platinum print is stored in contact with paper for prolonged period of time, the image may discolor the facing paper and result in transfer of the image.
Basic Process Overview (Contemporary Process)
This process uses platinum and palladium salts in combination with ferric oxalate (an iron process). The sensitizer is made in a shot glass with ferric oxalate and just a few drops of platinum and/or palladium. First, the sensitizer is applied to the paper and dried. Then, the negative is placed emulsion-side down on the sensitized side of the paper in a contact-printing frame. The frame is exposed to light, creating a faintly visible latent image. Once the exposure is complete, the paper is placed in an oxalate developer and the image comes up instantly. The image contrast is achieved mostly by exposure, not the developer, although contrasting agents can be applied to the process. Development is followed by acid clearing baths followed by water washing of the print. Mercury toner (aka developer) is prepared by mixing mercury chloride with water. The toner may be added to the sensitizer prior to its application to paper, developing solution, or both. The process is inherently acidic.
Housing and Storage Considerations
- Platinum, platinum-palladium, and palladium prints should be stored in good quality, neutral pH, paper-board folders, to protect from light, dust, and handling. Materials passing the Photographic Activity Test (P.A.T.) are suitable for use.
- An ideal temperature and humidity are 68 degrees F (20 degrees C) +/- 2 degree drift and 50% +/-5% variation over 24 hours.
Emergency Recovery Tips
- Handling wet paper can cause damage such as image abrasions, nicks, and tearing of the support.
- Mold can develop on or within the papers.
Helpful Treatment Techniques, Things to Know, and CAUTIONS!
- Paper supports can become brittle (from the acidic processing) and yellow. Cracks, breaks, and broken corners are common.
- Platinum and palladium are considered, robust, permanent media. However, mercury developed (aka sometimes called mercury toning) photographs can reduce in color over time and appear lighter brown.
- X-ray fluorescence (XEF) non-destructive testing confirmed that platinum prints can mirror in d-max areas (2014).
- Platinum and palladium image surfaces can be abraded along the tops of a rough paper and especially around the edges from wear over time. Handle with care and on the edges as with all photographic material.
- Images in contact with cellulosic materials (such as papers or photographs in a stack) for long periods of time can transfer a dark, backward, mirror image on the material sitting on top of it (acid transfer).
- Platinum and palladium prints can be washed, and chemically bleached and light bleached with caution. Be cautious of using strong de-acidification processes unless pure platinum content is confirmed. De-acidification processes can be deleterious to a silver-platinum print. Also, inspect carefully prior to treatment for any friable-media retouching to the print.
- Some contemporary practitioners print platinum and palladium prints as the first layer, with colored gum bi/dichromate layers above.
- Barro, E. The Deterioration of Paul Strand’s Satista Prints, Topics in Photographic Preservation, (10) 2003, Washington, D.C.: Photographic Materials Group of the American Institute for Conservation, pp. 37-54.
- Danzig, R. Stieglitz: Photographic Process and Related Conservation Issues. Topics in Photographic Preservation (4) 1991, Washington, D.C.: Photographic Materials Group of the American Institute for Conservation, pp. 57-79.
- Gent, M, and J. Rees. A Conservation Treatment to Remove Residual Iron from Platinum Prints, The Paper Conservator: Journal of the Institute of Paper Conservation (18) 1994, London, IPC, pp. 90-95
- Gottlieb, A. Chemistry and Conservation of Platinum and Palladium Photographs. Journal of the American Institute for Conservation (34) 1994, Washington, D.C.: Photographic Materials Group of the American Institute for Conservation, pp. 11-31.
- Norris, D.H. Platinum Photographs: Deterioration and Preservation, Photographic Conservation 7 (2) 1985, Rochester (N.Y.), Graphic Arts Research Center - Rochester Institute of Technology, p. 1.
- Platinum and Palladium Photographs: Technical and Aesthetic History, Chemistry, and Connoisseurship. Symposium, October 21-24, 2014. Washington, D. C.: Foundation for the American Institution for Conservation
- Severson, Douglas. Alfred Stieglitz’s Palladium Photographs and Their Treatment by Edward Steichen. Journal of the American Institute for Conservation (34), 1995, Washington, D.C.: Photographic Materials Group of the American Institute for Conservation, pp. 1-10
- Von Waldthausen, Clara. Coatings on Salted Paper, Albumen, and Platinum Prints, Coatings on Photographs: Materials, Techniques and Conservation, Constance McCabe (editor), Washington, D.C.: American Institute for Conservation, 2005, pp. 78–95.
Process and Historic Material
- CAMEO: Platinum Paper: http://cameo.mfa.org/wiki/Platinum_paper; Palladium Print: http://cameo.mfa.org/wiki/Palladium_print
- Coe, Brian and Mark Haworth-Booth. 1983. A Guide to Early Photographic Processes. London: Victoria and Albert Museum
- Crawford, William. 1979. The Keepers of Light. New York: Morgan & Morgan. p. 199-212
- GEH Notes on Photography (Print): http://notesonphotographs.org/index.php?title=Palladium_Print
- GEH Notes on Photography (Print): http://notesonphotographs.org/index.php?title=Platinum-Palladium_Print
- Hafey, John, and Tom Shillea. 1979. "The Platinum Print. The History of the Platinum Print: A Reference to the Commercial, and Aesthetic Development of the Platinotype." Rochester, NY: Graphic Arts Research Center, Rochester Institute of Technology. http://www.kimeia.com/pdf/history.pdf
- Hendriks, Klaus B., with Brian Thurgood, Joe Iraci, Brian Lesser, Greg Hill. 1991. Fundamentals of Photograph Conservation: A Study Guide. Toronto, Ontario: Lugus Publications for the National Archives of Canada
- "History of the Platinum Print" http://www.danesphoto.com/pt_history.html
- Lavedrine, Bertrand (with Jean-Paul Gandolfo, John McElhone, and Sibylle Monod). 2007 (French version), 2009 (English Version). Photographs of the Past: Process and Preservation. Los Angeles, CA: The Getty Conservation Institute
- Nadeau, Luis. 1994. History and Practice of Platinum Printing. Third edition. New Brunswick, CANADA: Atelier Luis Nadeau.
- Norris, Debra Hess. 1980. "Eakins at Avondale: Discovery, Examination, and Treatment of his Platinum Prints." p. 53-61. American Institute for Conservation Annual Meeting Pre-prints. Washington, D.C.: American Institute for Conservation.
- "Platinum Photography", The Collector's Guide. http://www.collectorsguide.com/fa/fa031.shtml#RESOURCES
- Reilly, James M. 1986. Care and Identification of Nineteenth-Century Photographic Prints. Rochester, NY: Eastman Kodak
- Ware, Michael J. (Mike). 1986. "An Investigation of Platinum and Palladium Printing." Journal of Photographic Science vol. 34 (5-6): 165-177.
- Alternative Photography (How To): http://www.alternativephotography.com/wp/processes
- Analog Photography Users Group (APUG): http://www.apug.org/forums/home.php
- Arentz, Dick. 2005. Platinum & Palladium Printing, second ed. Waltham, MA: Focal Press (Elsevier).
- "Platinum Photography", WIKIPEDIA: http://en.wikipedia.org/wiki/Platinum_Photography
- Van Keuren, Sarah. 2004. A Non-Silver Manual: Palladium http://www.alternativephotography.com/wp/processes/platinum/a-non-silver-manual-palladium
- Ware, Michael J. (Mike). "The Platino-Palladiotype Process." http://www.mikeware.demon.co.uk/platin.html
- Ware, Michael J. (Mike). "The Eighth Metal: The Rise of the Platinotype Process." http://www.mikeware.demon.co.uk/eighth.html