 |
The Ziatype Compared to the Ware-Malde Process It has come to my attention that there has been some confusion concerning the chemical and functional differences between my Ziatype system and the Ware-Malde system. This paper is my argument in what has become a heated but gentlemanly disagreement over the nature of the two processes. Historically both processes stem from the earlier work of Captain Pizzighelli. Pizzighelli, along with Captain Abney, Hubl, and Willis, laid most of the groundwork for platinum and palladium printing as we know it today. Captain Abney’s complete book is available for downloading on this website. Most of this early work laid down by these gentlemen were variations on the theme of platinum printing that we are most familiar with today, the traditional ferric oxalate, noble salt, and wet development method. Pizzighelli co-authored with Hubl, a book on platinum printing. A little later, he took another tack and developed a printing out method of making platinum prints. Essentially his method, as described (i) used ammonium ferric oxalate or sodium ferric oxalate, potassium chloroplatinite and a humidified paper base for achieving the printing out effect. There was apparently a commercial version of this paper and I have seen reports that Steiglitz used it for a brief time. The process apparently fell into oblivion after a short period. In 1986 Dr. Michael Ware published a paper in the Journal of Photographic Science (Sept-Dec 1986, Vol. 34) published by the Royal Photographic Society, describing a process quite similar to Pizzighelli’s, except Ware substitutes ammonium chloroplatinite for Pizzighelli’s potassium chloroplatinite. This substitution according to Ware was to achieve a higher solubility and to make the chemically coated surface of the paper more hygroscopic. He also states that ammonium chloropalladite can be used as well. Over the years, Ware and his collaborator Pradip Malde, have evolved an extensive workable system of printing based on this principle. Ware in the 1986 JPS article cites Pizzighelli’s earlier work on the traditional wet development process but not his work on POP platinum printing. Whether Ware was unaware of Pizzighelli’s earlier work on a POP process, or if this was an oversight is not known. Bostick & Sullivan have been in business since 1980 and have had a telephone Helpline since its inception. I first became aware of the Pizzighelli POP method in the early 80’s as several customers had found descriptions of it in the historical literature and reported varying degrees of success using it. I had also received reports of what appeared to be totally independent inventions of the POP process. In the early 80’s Bostick & Sullivan was a very tiny company and not too many printers knew of our powdered ferric oxalate. Several guides to platinum printing in that period were recommending the use of ferric ammonium oxalate, which was then as now, commercially available. If one uses ferric ammonium oxalate to make a traditional palladium print, and does not get the paper totally bone dry, one will get a very strong printing out image. Most people would logically conclude that there are possibilities lurking about. This is quite likely how Pizzighelli discovered his method. Again, to their credit Ware and Malde took the ball and ran with it and produced a rational printing method using the Pizzighelli principle. The impression that those of us at B&S got about the Ware-Malde process through our well connected Helpline was that this was not a process for the faint of heart. Humidity is a crucial control element in the Ware-Malde process and affects image color, contrast, and printing speed, as can be seen in Ware’s chart in the Notes section. My own experience in marketing platinum and palladium processes was that the POP aspect would be appealing to new printers, however the tricky humidification system would be a big turnoff. In late 1995 and early 1996 I began exploring the double palladium salts. The traditional one used in the wet process is sodium chloropalladite. I was interested primarily in color control. I had hopes were that I’d find one that made cool toned prints and one that made warm toned prints. ( I also fantasized, greens, reds and blues, which were never to arise!) I began going through the periodic table making various double salts of palladium. Among the ones I tried were: potassium, sodium, ammonium, barium, zinc, tin, tungsten, magnesium, lithium and cesium. Either like tin, they didn’t make a salt, or like barium, precipitated out in the double oxalates. After reading in an old chemistry book that lithium chloride was assumed to be the most hygroscopic compound known, I immediately tried lithium chloropalladite in the belief that it may be very hygroscopic as well. The lithium salt, unlike the rest tended to produce an almost blue black image throughout a wide humidity range. Originally I was not particularly looking for a POP process, but the apparent hygroscopicity of this material pointed me in that direction. My thoughts on this were that if I could find a corresponding "brown" producing component that could be mixed with the lithium palladium salt, we might have a system for POP printing that was largely independent of humidity. Lithium was at the top of the periodic table, and is a fairly weird element in that some chemists surmise that it is really a gas masquerading as a metal. I guessed that one of the very heavy elements at the bottom of the chart may give very different printing characteristics. I quickly hit upon the cesium salt of palladium, and as luck would have it, characteristic tendency is to produce brown prints. The cesium salt, like the lithium salt, tends to be more hygroscopic than its cousins, though I say this only through observation, as I have no way to measure it accurately. I have concluded through testing that the two polar palladium salts in terms of color are lithium chloropalladite and cesium chloropalladite. There is a nice chemical symmetry to this as they are both double salts built on alkaline metal compounds. The lithium is at the top of the periodic table and is a very light element, the cesium is at the bottom, and is a very heavy compound. So far what had evolved was a printing system where very brown to blue black prints could be obtained in a very wide humidity range. This was a humidity range that could be set with little skill by a printer with a hair dryer. The system was also a pure palladium one, and did not need the expensive platinum salt. In fact platinum does not seem help print quality or permanence. All that was left for a fully chemically controlled system was to solve the contrast problem. I discovered that a solution of ammonium dichromate, used in varying concentration of from 2 to 20 percent depending on print size, produces a wide range of contrast without degrading or graining the image. The Ziatype is an evolving system. I have recently discovered that brown colors can also be chemically induced by the use of an 80% solution of sodium tungstate. This compound seems to mimic the affects of the historically used mercuric chloride but works with palladium as well instead of just platinum. It has none of the dangers associated with the mercury salt, and the color produced by the use of sodium tungstate is slightly different from that obtained with the cesium salt. The Ziatype system is an attempt to produce a pure palladium printing system based on Pizzighelli’s principle, but one where color and contrast were chemically controlled and where the paper humidity plays a minor control function. Ziatype and Ware-Malde
compared.
The Ziatype system, as you can see, is a not a knock-off or a repackaging of the Ware-Malde system, but an attempt to take Captain Pizzighelli’s basic principle and eliminate what I perceived as basic defects in the Ware-Malde system. The only common elements in the Ware-Malde system and the Ziatype system are the use of ammonium ferric oxalate to effect the developing out. This is of course Captain Pizzighelli’s discovery in the late 1800’s. The two palladium salts, the cesium and the lithium, are in the Ziatype system for a reason. They provide color polarity and eliminate the need for expensive platinum. They are not disguised analogs of the Ware-Malde’s ammonium salts. The Ziatype system is not a thinly disguised marketing scheme and in fact, could be seen as working against Bostick & Sullivan’s self interest due to the elimination of the more profitable platinum compound. We sell the ammonium chloroplatinite and the ammonium chloropalladite and all of the other compounds for the Ware-Malde system. It is of little economic interest to us as to which method is used. Some may say that in fact we may benefit more from our customers using the Ware-Malde system. However my philosophy has been that we economically benefit when printers have easy, controllable, and economical printing methods. Nothing quite helps our economic well being than having our customers be successful in their printing endeavors. The Ziatype is aimed at the casual to skilled printer. Its goal was to provide "dial-in" chemical controls for color and contrast, and to eliminate complex humidity controls. I think it comes very close to achieving those goals. This is not to denigrate Dr. Ware or Professor Malde. Their system provides excellent prints in the hands of skilled practitioners and they should be commended for their work. Particularly Dr. Ware’s work in the ferric salts and the ferric processes. His Cyanotype process and the Argyrotype process are landmark processes in the history of alternative process photography. Notes
Footnotes: |
|