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Platinum-Palladium Prints |
Purpose: To experiment with different parameters of platinum-palladium printing by
making prints with three different types of paper.
Platinum-Palladium prints differ greatly from the silver gelatin print made on photographic paper. The platinum-palladium metals are embedded in the surface fibers of the paper that is used in this method of printing. All of the prints produced by this printing method are unique. Unlike silver gelatin photography, platinum-palladium allows the photographer to hand coat their paper.
Platinum and palladium metals "are much more inert than silver and are therefore dramatically less susceptible to attack by impurities or atmospheric pollutants." Therefore, platinum-palladium prints are "desirable for both its archival endurance and particular aesthetic qualities."
There are many different papers that can be used for the platinum-palladium process. The difference in papers have a dramatic effect on the outcome of the print.
Unlike silver gelatin prints, there is never a glare that is visible on the platinum-palladium print. Platinum-palladium holds low sensitivity causing the printer to use an ultraviolet light source. A darkroom therefore is unnecessary in this process.
In order to begin our experiment, we set up a still life involving grays, blacks, and whites. We then set up the 4x5 camera and exposed nine different sheets of film. The nine sheets were exposed at three different aperture settings on the camera. Three were exposed two stops down from the normal exposure, three were exposed at the normal exposure and three were exposed at two stops up from the normal exposure. The normal exposure was obtained from a light meter reading of the still life. The gray area of the still life had a light meter reading of 8/16, the black had a reading of 0/16, and the white area had a reading of 12/16. Our objective was to obtain the perfect negative in order to make our three prints.
Exposures:
A= normal (-) 2 stops
B= normal exposure
C= normal (+) 2 stops
The first three negatives we exposed at f22 for 1/15 seconds. The next three negatives we exposed at f16 for 1/8 seconds. The last three negatives we exposed at f16 for 1/2 seconds.
In order to produce the perfect negative, we developed one negative from each different setting at different developing times:
1=normal (-) 30% developing time Negatives
2=normal developing time
3=normal (+) 30% developing time
The negatives are labeled, 1A, 1B, 1C, 2A, 2B, 2C, 3A, 3B, 3C
The normal development time was determined to be 16 minutes. Therefore, we developed the 1’s for 12 minutes and the 3’s for 20 minutes.
To develop our negatives we used pyro developer. We used trays in complete darkness in order to develop our negatives. Pyro consist of 1 part A + 2 parts B + 100 parts water to make the working solution. Solution A is comprised of metol and sodium bisulfite. Solution B consist of sodium metaborate ("Kodalk").
The processing steps are as follows:
Our next step was to make three prints. We made the first print with Crane's business card stock. The second print was made with Somerset textured 250g/m^2. The third print was made with Van Gelder Simili Japan paper. We first cut the paper to accommodate the size of our print. We then hydrated the paper for five minutes. In order to hydrate, we attached the paper to a magnetic strip on a piece of covered glass and placed this over the water bath. Using a glass rod, we coated the paper with .4cc of platinum-palladium. This solution consists of 27 g of ammonium iron oxalate trihydrate and 50 cc of distilled water at 50C/122F, 5 grams of Ammonium tetrachloroplatinate (II) and 20 cc of distilled water, 5 grams of Ammonium tetrachloropalladate (II) and 25 cc of distilled water. We made four passes on each piece of paper. Next, we dried the paper in the food dehydrator with the temperature at 104 degrees Fahrenheit for ten minutes. After the paper had dried, we rehydrated for fifteen minutes. Then we placed the paper and the negative in the contact printing frame. When we had lined up the negative perfectly with the paper, we placed the frame in the UV box for 2 minutes and 50 seconds.
Before developing, we rehydrated the print for 2 minutes. Then we placed the print in the solution of EDTA #1 for ten minutes. Next, the print went into fresh water for 30 seconds. After this step, we then placed the print in Kodak hypo clearing agent for 15 minutes. Then we put the print into fresh water again for 30 seconds. Next the print was placed into the EDTA #2 for 15 minutes. Finally the print went into running water for 30 minutes. After removing the print from the wash, we placed the print on the drying racks to dry. This process was used for all three prints.
To make the EDTA #1 working solution, "weigh out 50 g of disodium EDTA and slowly stir it into about 900 cc of warm distilled water (40-50C/104-122F) until dissolved." The Hypo clearing agent is made according to the manufacturers recommendation. The EDTA#2 consists of the same chemicals as the EDTA#1.
Our next step in the experiment was to use the colorimeter to find a numerical calculation of color contrast in the prints. We used three specific areas of the print to test for gray, white, and black. This reading is based on a LAB scale that reads from 1-100. Here 1 is the purest black and 100 is the purest white.
Our final step was to test the acidity of the three papers. Approximately 1 gram of paper was shredded and put into a beaker with 70 cc of distilled water. Then the paper soaked for ten minutes. Then we tested the acidity with the pH meter.
The negatives produced vary in tonal values as well as in contrast. 1 A, 2 A, and 3 A, all appear the lightest of the negatives developed. The variation in darkness of the negative is due to the difference in development times. Because these three negatives were underexposed they appear much lighter than the other six negatives. Negatives 1 B, 2 B, and 3 B, all appear to have the most accurate exposure time to produce the perfect print. Because of the difference in development time, negative 2 B is the perfect negative. 1 C, 2 C, and 3 C appear to be overexposed, and the negatives appear much darker than the other six. Due to the differences in development times, the contrast in the negatives vary.
The papers we used varied in their textures, sizing, and color. The Crane's Business Stock Card paper was cream color with a smooth surface. Compared to Somerset, the Crane's is thin. Yet when compared to the Japanese paper, the Crane's was much thicker. The Somerset paper is very thick and is white. The sizing in this paper is large. The Japanese paper was cream colored and very flexible. This paper was also thin.
When coating the Crane's and Japanese paper, the platinum-palladium was even distributed across the sheet of paper. However, the Somerset paper absorbed the solution quickly and unevenly causing unequal distribution. This is due to the calcium carbonate present in the paper. After four passes on the Japanese paper there was still some solution left standing. The Crane's paper caused no problems when coating. The color of the platinum-palladium solution is a light yellow and orange color. After drying the coated papers, there was no change in color.
When drying the paper, the Crane's and Japanese were dry after ten minutes. However, the Somerset was still wet after drying. This is due to the sizing of the paper. The sizing effects the negative sticking to the platinum-palladium while making the print.
After exposing the papers in the UV box, the image appears on the paper. The areas of the negative that are very black turn white on the paper, and the areas of the negative that are very light turn dark on the paper. In our prints, there are many different tonal values present. The paper that was covered with the yellow-orange solution, not covered by the negative, now appears black.
Once the prints were placed into the EDTA#1, we saw the platinum-palladium begin to wash off. The color of the print did not change when the solution washed off. The color of the EDTA #1 turned a clear, orange color. The other chemicals did not have a color change or a visible effect on the prints.
[Missing Images]
Acidity testing:
We measured 1.081 grams of the Van Gelder Simili Paper, 1.0116 grams of the Cranes business card stock paper, and 1.1553 grams of the Somerset paper in the balance scale. The acidity for the Van Gelder paper was 5.62 pH. The Cranes paper had a pH of 7.45. The Somerset was at 7.57 pH. The acidity of the paper effects the quality of the prints that are produced.
From our experiment we believe that the best print produced was on the Crane's Business Card Stock paper. According to Pradip, the acidity of paper for printing platinum-palladium prints should be between 7.3 and 7.5. Our acidity testing showed that Crane's paper should work the best, and we found that to be true. The colorimeter testing helped to prove the variations in color in platinum-palladium prints. Although the Crane's and Japanese papers held close readings, the Crane's paper appeared richer in blacks, whites, and grays.
Malde, Pradip and Ware, Mike. The Ammonium System: a contemporary method for
making platinum palladium prints. Sewanee, 1997.