This is not a problem unique to the gelatin silver world, either. If you print with pt/pd, do you have ANY assurance that there will not be some trace contaminant in the paper or in the reagents you use, which will adversely affect the lifespan of the print? I think not.

Actually Paul, yes I do. This is in fact is the difference between being a chemist and a photographer and a wedding/printing tech with little knowledge. I have had conversations with B&S regarding their quality assurance. Nevertheless I order in big quantities both chemicals and papers and do some tests when I receive them to assure they are free of chemical agents other than those already specified. Even so, there is a curious similarity when you process a pt/pt print to one that is commonly used in industry and is called to "pasivate." In this process you "stabilize" a pipe for example by flushing it with an alkali first and then an acidic solution. As it happens pt/pd prints benefit from a slightly acidic environment when brushing in the emulsion, but given the current state of affairs with paper manufacturers most include alkali buffers to enhance preservation. The act of removing the buffer by introducing the paper in an mild acid bath in fact not only removes the buffer, but at the same time "degreases" and removes contaminants from the paper. If you then clear the print in a slightly alkaline solution, you are in fact neutralizing the paper and bringing it back to the best possible archival state.

Now, the obvious response to your statment is that this is a red herring as you cannot have the same assurances in the paper you use either. Furthermore, it is my understanding that ink jet poster papers have many organic fasteners for the inks, this cannot be good for the print even if you choose to ignore it. Even if it is not the case and as it was put the paper is 100% rag (which I doubt very much since it was expressly created for ink jet which benefits from ink fasteners) the fact that you guys do not process your paper and use it as is, it is more likely to include contaminats than a pt/pd print that has been processed.

Your 103 year old example once again it does not apply, if we are going to use examples like this, then we know that the pyramids have been around for thousands of years, the straw huts made at the same time are long gone. This is exactly the same difference between talking about a mineral/metallic compounds (silver, pt, pd) and an organic compounds (carbon). While as some beleive carbon does not "oxidize" (not stricly true but for the purposes of this discussion good enough) it is far more suceptible to other kinds of attacks to which metals, even silver are imprevious.

I think much of the reason why you read little about fungus and other biological problems is that they can be largely controlled by rigid environmental controls - that is, control over humidity, etc.

Sorry Paul, I am talking about the prints in the houses of photographers in Houston. I know my house was neither humidity or temperature regulated at least not so that it could be considered a preservation place. As I said, I doubt you could treat an ink jet poster the same way I treated some of my prints while I was moving around the country.