salt printing as practise for platinum/palladium

[Jorge Gasteazoro]

Michael, I thought about when I wrote the message, but without a lab or spending some money it is impossible to accuratelly tell how much of it is replaced. A "visual" check with a densitometer is actually a very accurate indication of the degree of removal.

We can think there are two possible scenarios. One the pd completly "coats" the silver thus inhibiting bleaching, and the other one is that pd replaces the silver. Occam razor tell us that if we hear hoves we should think horses not zebras...or KISS. I think that if you heated the pd toning soultion, the reaction would be 100% or so close to it that for all practical purposes it makes a pd print.

I wish I had access to a lab, since the implications this experiment has can be very interesting. Making a pure pt print is a PITA, but if this reaction behaves the same way with pt then making pure pt prints would be no longer so difficult and much, much cheaper...

[Michael S. Briggs]

Re how much silver is replaced by palladium when a kallitype is toned with palladium: as already stated, there are two main hypotheses. Hypothosis 1 is the coating hypothesis, which has two sub-variants: 1A is that the palladium coats the silver grains and 1B is that the palladium replaces a surface layer on the grains. Hypothesis 2 is that the palladium replaces essentially all of the silver, essentially all meaning something like 95%.





The tone, bleach and measure density experiment that Sandy conducted answers the most important question: it shows that fully-palladium-toned kallitypes resist chemical attack more like palladium prints than like kallitypes. This is important because it shows that fully-palladium-toned kallitypes will probably last almost as long as a palladium print. I agree with Sandy's statement "What I gather from this test is that a palladium-toned kallitype should have great permanence since virtually all of the silver has been either replaced or coated with palladium."





However, my opinion is that Sandy's experiment is of very little use deciding
between the hypotheses of "replace or coated with palladium". Under both hypotheses a fully-palladium-toned kallitype could be highly resistant to bleaching. Obviously, if the silver is fully replaced the print will resist bleaching as if it were made only with palladium. But under the Hypothesis 1, if the silver grains are essentially fully coated with palladium (either by an added layer or by a replaced layer), then the print will also be highly resistant to bleaching because the bleach won't be able to reach the silver.





My knowledge of chemistry isn't deep, so take the next two statements with a caveat. I doubt that a simple chemistry experiment that can be done with equipment typically used by even advanced darkroom workers will be able to distinguish between the two hypotheses. I also guess that the more likely toning action is the first hypothesis, coating, rather than the near total replacement of the second hypothesis.





If the first hypothesis of coating is correct, the fraction of silver in the toned print will vary with grain size because large grains have a smaller ratio of surface area divided by volume.





Unless someone convincingly demonstrates the second hypothesis of near total replacement, I think it would be highly misleading to call a palladium-toned kallitype print a palladium print. I am surprised that this idea was suggested, considering the strum-und-drang on another recent thread about calling ink jet prints carbon prints. If essentially total replacement is demonstrated, then the issue about whether using the term palladium print is appropriate for a fully-palladium-toned kallitype would be whether the difference in the actual steps taken to reach the final print were too different. Based on the long usage history of platinum/palladium and kallitype, my opinion is that pladium-toned kalliptypes should not be called palladium prints even if the silver is fully replaced.

[sanking]

I am responding to several messages so I hope that all points are covered.

1. I think my experiment demonstrates that Jorge was more right than me. I had thought that a toning bath of 10-15 minutes with a toning solution rich in palladium would entirely replace the silver. This did not happen and it is therefore my belief that it would not be appropriate to call a palladium toned kallitype a palladium.

2. Since the silver was not entirely eliminated, either through replacement or plating, the issue of replacement versus plating was rendered mute. Had there been no loss in density, which would have demonstrated 100% plating or replacement of the silver with palladium, further testing would have been warranted to determine exactly what the reaction was.

3. Further investigation shows that there is no good scientific literature on toning with platinum and palladium, and in fact the exact nature of the reactions are not well understood even by experienced scientists. As far as I am able to determine no one has ever done any testing to show whether toning results in replacement of plating, or if both, the relative percentages of each. But, there are apparently tests, both destructive and with instruments, that can show this.

Even though the tests did not demonstrate what I expected, they were nevertheless useful in showing that toning a kallitype print with palladium provides great protection against oxidative reactions, and thus gives great permanence. 100% protection against oxidative reactions would probably be accomplished by further toning the remaining silver metal with a polysulfide toner. I plan to continue testing along these lines as soon as I acquire the necessary chemicals.

[Michael Mutmansky]

Sandy,

I had one other question regarding the visual compatability of a pd toned kallitype and a traditional palladium print.

When you printed the kallitype and the pd print, what developers were you using for both, and what temeratures? I ask this because, as I'm sure you know, the color of the tone can vary substantially based on the chosen developer and the temperature.

With pd, if you print with sodium citrate you will get a fairly cool print, relative to a potassium oxalate developed print. The difference is much more substantial if you heat the potassium oxalate to 120 degrees (or even higher). Some peoiple develop at as high as 180 degrees for a very warm (almost sepia) print.

Is it possible to print the kallitype and achieve a warm print, and then pd tone it to keep the warm tones? I used to print 50/50 pt/pd, but I switched to pure pd and hot developer because I prefer the warmer tones that it produces.

So the question is how much flexibility is there to tune the image tone as there is in the traditional pd process?

---Michael

[sanking]

Michael Briggs wrote:

"Unless someone convincingly demonstrates the second hypothesis of near total replacement, I think it would be highly misleading to call a palladium-toned kallitype print a palladium print. I am surprised that this idea was suggested, considering the strum-und-drang on another recent thread about calling ink jet prints carbon prints. If essentially total replacement is demonstrated, then the issue about whether using the term palladium print is appropriate for a fully-palladium-toned kallitype would be whether the difference in the actual steps taken to reach the final print were too different. Based on the long usage history of platinum/palladium and kallitype, my opinion is that pladium(sic)-toned kalliptypes should not be called palladium prints even if the silver is fully replaced."

The issue raised by me on the other thread, i.e. real carbon versus inkjet carbon, was primarily one of a hand-made process versus a machine process. Any comparison of the issues raised in that thread to the issues of this thread is simply too silly to merit a serious response. I am really quite surprised that you would have even considered such a comparison appropriate.

You may or not be aware of the fact, but in pt/pd printing there is a long history of adding metals other than platinum and palladium (gold, silver and mercury) to the sensitizer, and the result is a final image that comprises a significant percentage of a metal other than pt/pd. What would you call an image that consists of 90% pt/pd and 10% gold? Or one that comprises 90% pt/pd and 10% silver? Or 90% pt/pd and 10% mercury. I know people who are using additives in this way on a regular basis. Sure, many of the folks working in this way carefully note on the print the actual metals used in the sensitizer but it would never cross their mind that the final image should not be called a real pt/pd print, even though the final image comprises a high percentage of a metal other than platinum or palladium

Finally, we know from destructive tests conducted by the French chemist Etiennne that actual silver replacement of up to 80% has been achieved in gold toning of albumen and salted paper prints, so in theory actual replacement, and not just plating, is possible in toning kallitypes with more noble metals.

[sanking]

"So the question is how much flexibility is there to tune the image tone as there is in the traditional pd process?"

Michael,

I use only sodium citrate for developing kallitypes. The resulting image is a very warm brown tone, much warmer than you get when developing pt/pd in warm potassium oxalate.

Subsequent toning of the kallitype image will give a very neutral black image if toning is done with only platinum, and a much warmer brown if toning is done with only palladium. However, the very warm brown that you get from toning with pure palladium is not quite as warm as the color that you get from developing straight palladium in a warm potassium oxalate solution.

I have not done any testing to see if it is possible to get even warmer brown tones with toning.

[Donal Taylor]

Michael Briggs wrote:

"Unless someone convincingly demonstrates the second hypothesis of near total replacement, I think it would be highly misleading to call a palladium-toned kallitype print a palladium print. I am surprised that this idea was suggested, considering the strum-und-drang on another recent thread about calling ink jet prints carbon prints. If essentially total replacement is demonstrated, then the issue about whether using the term palladium print is appropriate for a fully-palladium-toned kallitype would be whether the difference in the actual steps taken to reach the final print were too different. Based on the long usage history of platinum/palladium and kallitype, my opinion is that pladium(sic)-toned kalliptypes should not be called palladium prints even if the silver is fully replaced."

The issue raised by me on the other thread, i.e. real carbon versus inkjet carbon, was primarily one of a hand-made process versus a machine process. Any comparison of the issues raised in that thread to the issues of this thread is simply too silly to merit a serious response. I am really quite surprised that you would have even considered such a comparison appropriate."

I've always editioned my prints whether silver gelatin or Pd. Do others edition theirs or not? I'm starting to think perhaps not?

[sanking]

"I've always editioned my prints whether silver gelatin or Pd. Do others edition theirs or not? I'm starting to think perhaps not?"

I am curious as to what you have found in this thread that has anything at all to do with editioning? Editioning was about the last thing on my mind.

[Donal Taylor]

""I've always editioned my prints whether silver gelatin or Pd. Do others edition theirs or not? I'm starting to think perhaps not?"

I am curious as to what you have found in this thread that has anything at all to do with editioning? Editioning was about the last thing on my mind."

What you said below, as quoted:

"The issue raised by me on the other thread, i.e. real carbon versus inkjet carbon, was primarily one of a hand-made process versus a machine process."

I had never considered my printing process that way, as hand made versus machine made. If I want to consider my prints as hand-made, why edition them, apart from convention? It would make more sense just to sell each one as an individual print, especially the platinum prints.

Years ago when I first started platinum printing I didn't number them, mainly because I made very few and sold even fewer. It was only when I started selling through a gallery that they asked for editions and I went along with it and have done so ever since.

[Michael S. Briggs]

The issue raised by me on the other thread, i.e. real carbon versus inkjet carbon, was primarily one of a hand-made process versus a machine process. Any comparison of the issues raised in that thread to the issues of this thread is simply too silly to merit a serious response. I am really quite surprised that you would have even considered such a comparison appropriate.





It seems to me that part of the issue in the Anybody else getting heartburn with the new 'Carbon Print' ? is whether it is proper to use a term with a long established meaning for a new process, e.g., will this mislead buyers about what they are getting? Some makers of some types of inkjet prints want to call them "carbon prints" on the basis that the pigments used contain carbon, while some others object that this term already has a meaning and object to assigning a new meaning to the term. In comparison, palladium-toned kallitypes probably contain a lot of palladium and the photographic literature hasn't called these prints palladium prints, so would it be misleading to start using the term "palladium print" for palladium-toned kallitypes? It is true that the differences in process between carbon print and inkjet print is much greater than the difference between palladium-toned kallitype and palladium print.