After flattening the prints done that prompted this thread, I've examined them and all of the Kentona sheets have at least a little staining along the safe edges. Is it possible that this is an age of paper issue? The images don't seem to be affected much, if at all.
I understand about the stop bath, and while I usually do use and acid stop, I'd run out before doing this batch. More is on order. I appreciate everyone's input! Good to know that an acid stop won't really affect the longevity of TF4.
You guys recycle your stop-bath? I usually just throw 60ml into a 5L container (with water) and one-shot it.
Originally Posted by Sirius Glass
Although as I do more printing I might reconsider just reusing it. I usually dilute the one shot working solution 1:2 in the tray anyways.
Hello, i have been thinking of posting a similar thread, and the issue of contamination is interesting. I work in a lab were we print mostly ilford warmtone. We have not, in the recent past had any problems with yellow staining when using sheet paper of any size, however, when we print murals we usually get yellow staining. This yellow is only along one edge, which is one end of a roll of mural paper, so I always chalked it up to manufacturing. As it is only in the boarder and only creeps in an inch or so it gets trimmed when mounted and we then forget about it. This past week I noticed it on two murals and went back and looked at the test strips which did not have the yellowing? We roll our murals thru long shallow trays that hold about a gallon of chemistry. Our stop bath is sprint, mixed double the strength our fixer is acidic (i think) NH5. We drain quickly and certainly not fully, but I wouldn't say we are any different with sheet paper. When fixing, we run prints thru a first fixer for 3minutes min, then a second fresh fix for 5. If we are making second or third prints the second print is going into a pretty fresh first fix (which was the second fix of the first print) and then a second fresh fix for 5. We have done a capacity check on the first fixer and it has plenty of life left for the second print not to mention that that print then gets a second fresh fix as well, but we still get staining. Any thoughts, questions or suggestions, would be great. If it is contamination or fogging, why would it only be on one edge? Thank you
I think it appears that way because prints are almost always developed to completion.
Originally Posted by dancqu
Water-bath development for contrast control is an example where water doesn't stop the development.
As I understand it an acid stop halts development so the developer doesn't hit a silver-laden fix in an active state. The stop bath, of course, has no dissolved silver in it.
Two bath developers like Diafine work on the principle that a lot of developing agent is carried in the emulsion and it takes a good bit of time for it to diffuse out.
I have no idea - just throwing out a speculative question: is the roll ever held vertically so the liquid would migrate to the one edge?
Originally Posted by bjames
Ansco 130 = acidic.
Originally Posted by Sirius Glass
What? With all that sodium carbonate in it, it most certainly will be basic, not acidic.
This needs repeated. PE has pointed out that TF-4 is buffered and can handle an acidic stop. And remember, you should let the print hang over the stop bath tray and let the excess stop on the surface of the print drain off the print.
Originally Posted by MattKing
If you are really concerned about the TF-4, then try another fix, like Ilford Hypam or Kodak Rapid Fix and then you don't have to fret over such things.
"I think it appears that way because prints are
almost always developed to completion."
The 10 and 30 second Kodak and Ilford quick dips are
no quicker at washing out the developer than same time
dips in H2O. The acid dips do though impart an overall
acidic character to the paper making them compatible
with the acid fix. More important in the days of the
ubiquitous fix with hardener.
"Water-bath development for contrast control is an
example where water doesn't stop the development."
Water bath technique calls for little or no agitation in
the water bath. So the slow stop. Several cycles are
usual; back and forth then back and forth then ... .
"As I understand it an acid stop halts development so
the developer doesn't hit a silver-laden fix in an
So too with a water stop. As the print developer is
diluted it's ph is plummeting. Much diluted and with
a ph nearing 7 the developer's activity nears zero.
"Two bath developers like Diafine work on the
principle that a lot of developing agent is carried
in the emulsion and it takes a good bit of time
for it to diffuse out."
Once again little or no agitation. Also, the
second B bath is quite alkaline. More so
than than TF-4. Dan
"I have no idea - just throwing out a speculative question: is the roll ever held vertically so the liquid would migrate to the one edge?"
Thanks Nicholas, thats a great observation, yes we do tilt it to one end to drain. Im not sure what it means but if thats the edge which also fogs that would be very telling. I will have to pay attention to that specifically next week.