Natha Congdon
2-May-2002, 23:31
(Warning: Long-winded thread only of interest to obsessive alt photo types!)
I've been printing Pt/Pd for about a year, mostly 12X20 negs (HP5+/pyro) on plat inotype paper, and feel like I'm getting pretty good control of the basics now, except for one painful and (to date largely unavoidable)fly in the ointment. My test strips, usually printed at about 8X10 or so, almost always seem to have a s moothness that I can get only intermittently in the full 12X20s. I use the same paper (although the 11X14 version) for the test strips, and have been through se veral batches of paper and several seasons of weather here in Baltimore with abo ut the same results. The 12X20s look a bit grainy, with the grain often looking slightly dark, at the extreme almost like the print was dirty from being stepped on (usually it's more subtle, but side by side against the test strips, no ques tion at all that the difference is there.)
Hypotheses explored and rejected:
1. Chemicals too cold. I've heated them gently in a water bath, even kept them w arm for several minutes to make sure that whatever is supposed to happen when th e chemicals get above 70F has time to happen. My workspace never gets below 65F. I warm the coating rod, paper and work surface as well as the chemicals.
2. Too much restrainer. Rarely use much at all, never as much as a 1:1 ratio, us ually more like 5:1 FeOx to FeOx with restrainer.
3. Too rough on the paper. I've gotten to the point, I think, of being really qu ite light with the rod, certainly no rougher on the 12X20 than the 8X10 (I'm an eye surgeon, so I think I've got a pretty light touch!)
4. Have been printing with pure Pd, which does seem to help a bit, but not elimi nate the problem.
5. Something in the developer. Use the same for the test strips and full-size pr ints, and have noticed the prob with Sullivan cold bath, K oxalate and citrate d evelopers.
6. Since I don't usually wash test strips for a full 20 min, I thought maybe too long a wash was roughing up the surface of the paper. No dice: a shorter wash t ime on a trial basis didn't help.
Hypotheses not yet tested, but would prefer to avoid Sysiphean agony of it all:
1. Reduce the proportion of FeOx to metal salts (recommended in the Sullivan/Wee se book I think, or is it Arentz?)
2. Use a 21 inch rod to coat 12X20 the long way (Carl Weese suggests this I thin k, specifically to go "with the grain" on Platinotype paper. Don't ask me!)
3. THe graininess is coming from too much metal salt, might be helped if I mask the borders or even reduced my volume of coating (I use 8 ml for 12X20, almost e xactly 3X what I use for my 8X10 test strips.)
4. Something fiddly about the ORDER in which one mixes the FeOx and metal salts, suggested by Nadeau.
ANY suggestion to help with this extremely vexing problem would be greatly appre ciated, especially if it requires obsessive attention to some detailed little "l ucky" ritual, the purpose of which is only vaguely understood!
Who needs Prozac for obsessive-compulsive disorder when you can treat it so much more expensively and satisfactorily with Platinum salts!
Thanks in advance,
"Bewildered in Baltimore" (Nathan Congdon)
I've been printing Pt/Pd for about a year, mostly 12X20 negs (HP5+/pyro) on plat inotype paper, and feel like I'm getting pretty good control of the basics now, except for one painful and (to date largely unavoidable)fly in the ointment. My test strips, usually printed at about 8X10 or so, almost always seem to have a s moothness that I can get only intermittently in the full 12X20s. I use the same paper (although the 11X14 version) for the test strips, and have been through se veral batches of paper and several seasons of weather here in Baltimore with abo ut the same results. The 12X20s look a bit grainy, with the grain often looking slightly dark, at the extreme almost like the print was dirty from being stepped on (usually it's more subtle, but side by side against the test strips, no ques tion at all that the difference is there.)
Hypotheses explored and rejected:
1. Chemicals too cold. I've heated them gently in a water bath, even kept them w arm for several minutes to make sure that whatever is supposed to happen when th e chemicals get above 70F has time to happen. My workspace never gets below 65F. I warm the coating rod, paper and work surface as well as the chemicals.
2. Too much restrainer. Rarely use much at all, never as much as a 1:1 ratio, us ually more like 5:1 FeOx to FeOx with restrainer.
3. Too rough on the paper. I've gotten to the point, I think, of being really qu ite light with the rod, certainly no rougher on the 12X20 than the 8X10 (I'm an eye surgeon, so I think I've got a pretty light touch!)
4. Have been printing with pure Pd, which does seem to help a bit, but not elimi nate the problem.
5. Something in the developer. Use the same for the test strips and full-size pr ints, and have noticed the prob with Sullivan cold bath, K oxalate and citrate d evelopers.
6. Since I don't usually wash test strips for a full 20 min, I thought maybe too long a wash was roughing up the surface of the paper. No dice: a shorter wash t ime on a trial basis didn't help.
Hypotheses not yet tested, but would prefer to avoid Sysiphean agony of it all:
1. Reduce the proportion of FeOx to metal salts (recommended in the Sullivan/Wee se book I think, or is it Arentz?)
2. Use a 21 inch rod to coat 12X20 the long way (Carl Weese suggests this I thin k, specifically to go "with the grain" on Platinotype paper. Don't ask me!)
3. THe graininess is coming from too much metal salt, might be helped if I mask the borders or even reduced my volume of coating (I use 8 ml for 12X20, almost e xactly 3X what I use for my 8X10 test strips.)
4. Something fiddly about the ORDER in which one mixes the FeOx and metal salts, suggested by Nadeau.
ANY suggestion to help with this extremely vexing problem would be greatly appre ciated, especially if it requires obsessive attention to some detailed little "l ucky" ritual, the purpose of which is only vaguely understood!
Who needs Prozac for obsessive-compulsive disorder when you can treat it so much more expensively and satisfactorily with Platinum salts!
Thanks in advance,
"Bewildered in Baltimore" (Nathan Congdon)