Francesco,

In my own work I have not noticed any difference in "punch" between negatives made with the 1:1:100 dilution and those made with the 2:2:100 dilution. Using the short times that are needed for developing with SBRs of 9 and greater we would expect to see less staining than with the longer times, and you would have less staining with the 2:2:100 dilution than with the 1:1:100 dilution, other things being equal. This may be what you are experiencing.

My article does not address the issue of matching films to a specific dilution. That would be an enormous undertaking that would require extensive testing, printing, and print evaluation. What I would basically recommend is that alternative printers use the 2:2:100 dilution for all SBRs of 7 and less, and the 1:1:100 dilution of SBRs of 8 and more. I recommend the 1:1:100 dilution for all forms of projection printing. This is of course consistent with Donald’s comment that “it is not a matter of matching films to Pyrocat dilutions so much as matching dilutions for desired density ranges in the negatives.” And to a certain extent my recommendation is based on the desire to keep development times at more than five minutes whenever possible, and not on the fact that I have found any advantage in one of the dilutions.