Originally Posted by Kerik
I made this determination based on bleaching of untoned kallitype prints and Pt./Pd. toned kallityes. An untoned kallitype in a strong solution of R-14 bleach will be reduced to no image in about five minutes. A Pt./Pd. toned kallitype will retain up to 97-99% of its density after extended bleaching in the same solution. The theory is that toning either converts the silver metal to Pt./Pd., or encapsulates it, and the bleaching tests tend to confirm this. Even chemists disagree about the exact nature of toning but laboratory analysis has been reported that strongly suggests that in toning with gold or Pt./Pd. silver is in fact converted to the more noble metals. In any event the practical result is that toning appears to give a kallitype print the same level of protection from oxidation as a regular Pt./Pd. print.
However, since the replacement of silver metal with the Pt/Pd. metal is not 100% complete I will concede that a Pt./Pd. print may have some slight advantage in terms of archival quality. But I think it most probable that other factors such as care in processing, quality of the paper support, and method of storage are far more important in the long run to print stability. It is not unusual to hear of silver prints from the last century toned with gold and Pt/Pd. that have survived in pristine condition because of good storage conditions and of Pt./Pd. prints in very bad condition from poor storage conditions. Indeed, even carbon prints on poor supports often show deterioration.
As for the other issues I would like to address once again the comparative issues of cost, time and stability between making toned kallitypes and Pt./Pd. prints because my experience simply does not agree with yours. Assessments are often based on emotional factors that have little or nothing to do with reality. I agree that in the end one will not be successful with any alternative process unless you love what you are doing, but why one comes to love doing one thing and not another is not always a product of pure reason and logic. You, for example, state that you find kallitype a PITA but love gum printing. I, on the other, see no practical difference in making toned kallitypes and regular Pt./Pd print, but find no pleasure at all in gum printing.
So we have different opinions about working procedures, but cost and time can be reduced to fact, not opinion, and I have some further thoughts on both.
Cost I stand by my earlier estimate that the cost of a toned kallitype print of 12X20 is about 1/5 (and less than that if you double coat) than hat of a regular Pt./.Pt. print. My paper costs, based on buying in quantity, are typically $1.50 to $2.50 per 22X30 sheet, from which one can make two 12X20 prints. So your finding that the cost of paper is roughly 50% of the cost of a print is simply not consistent with my own experience. Price per print will certainly vary with choice of paper but you would have to be paying over $5.00 per sheet of 22X30 paper in order for paper costs and chemistry costs to be the same for a 12X20 print. That is not what I have paid in the past for papers like Fabriano, Stonhenge, Lenox, the various vellums, or even Cot-320.
Time As you correctly observe, time is worth something so if it could be clearly established that it takes less time to make a regular Pt/Pd. print than a kallitype I would willingly concede this point. But in my work it does not. There are more steps involved in making a toned kallitype than a regular Pt./Pd. print but when you time the entire sequence of operations it take about the same time to make a large print with either process. In fact, since the exposure time is a significant percentage of the total time involved in making a print, and kallitype is more sensitive than Pt./Pd., the density of the negative being printed has a very big impact on the total amount of time needed to make a print, if you time from the moment of exposure to the end of wet processing. A couple of years ago you and I had this same discussion and I provided a typical flow-chart for making large prints with the two processes that clearly supports the above conclusion.
If I were making a lot of small images I think it is likely that making regular Pt./Pd prints would go faster, but for making a single large image, say 7X17 or larger, there is really no advantage in terms of time with either process, in my opinion. And my opinion is based on considerable experience in printing the same negative with both processes.
Last edited by sanking; 09-08-2004 at 02:46 PM. Click to view previous post history.