Removing stain from pyrocat negatives

[peter schrager]

Have some negatives and am using for cyanotype where the stain is proving to be too much...how to remove??

[koraks]

This question comes up regularly. Some say that strong selenium toning gets rid of the stain. Perhaps give that a try - but the drawback is, of course, that the selenium will add density and that may (will) defeat the purpose in this case.
Some say that a strong sulfite bath clears the stain. I tried. Didn't do anything. Still, worth a try.
Others say that an acid bath would be effective. Acid fixers have never done anything about the stain in my negatives and I'd skip this suggestion. Too much evidence against it.
The last remark I came across is from gary mulder (a user on here as well), who has argued that the grease from your finger(prints) will degrade the stain over time. I suppose smearing skin grease all over your negatives and waiting a few years is not a feasible option.

All considered, from my perspective, I'd say: reshoot the image and develop for this purpose, or print it using another process, or (if you're so inclined) scan it and inkjet print a negative for your cyanotype print.

[angusparker]

I've found that in the development process some fixers remove the stain entirely while others do not. Perhaps someone on the forum can suggest what to use and whether it will work post processing.