Yellowish base after selenium toning

[jose angel]

I notice a yellow cast on the base of my MG IV FB papers after the Se toning process. I`m using a very old Selenium Toner solution by Kodak.

Is it normal? Maybe it`s due to remaining fixer particles, or a bad washing procedure... I really don`t know. What do you think?

Sadly, it is "ruining" two of my three "finished" prints, which I prefer with the original clear white base. No problem with the purplish Se tone in the blacks. Is there any method to recover the original white base?

Any help is welcomed, thanks.

[MIke Sherck]

What is your fixing and, particularly, washing process?

Mike

[jose angel]

This time I fixed the prints for two minutes in Ilford rapid fixer, after that a wash on a tray, with running water, for around 20 minutes or maybe more. Then dry.
Twenty-four hours later, a second wash about fiveteen minutes, then 5 minutes in "old" Se toner, and a final wash on a big Nova slot washer for half an hour.
A bit of a hurry on process, I know. The still untoned print looks great, the toned ones are ugly, absolutely yellowish in the highlights and borders.

[Andrew O'Neill]

I have an old bottle of KRST (about 6 years old) and never had yellowing on MG IV fibre. What's your dilution? I dilute 1+9 with water. After fixing (I use the same fixer as you) and before toning the print gets a good rinse in water, followed by HCA, then a final rinse. How fresh is your fixer? Is your paper newish? Maybe it's time to buy a new bottle of KRST.

[ROL]

I am not aware that Se Toner can go 'bad'. One of the great bonuses of Se toning all your prints, whether to completion or not, is that it will indicate, pretty much as you have described, if they have been fixed properly. You should consider re-fixing any remaining prints before toning. The toner didn't ruin your prints, your fixing procedure and/or washing may have – it was actually more of an early warning system. I couldn't say whether you might recover whites by re-fixing after toning.

[Mark Sampson]

ROL is essentially correct. I'll add that sometime around 2001 or so I found a quart bottle of KRST; from the label design it was made before 1971. I tried it and it worked identically to the new bottle I had on hand. Whichever prints I toned with that old stuff still look good.. but in those days I double-fixed in F-6 non-hardening fixer, too.

[MIke Sherck]

I suspect insufficient fixing but I don't know. You fixed two minutes in Ilford Rapid Fixer; was that freshly mixed, at 1 part fixer to 4 parts water?

Mike

[Bill Burk]

I had the exact same thing happen to me when I fixed in a fresh single bath fixer and only rinsed prior to Selenium toning. Since I don't have the same problem when I wash for at least 2 hours prior to toning, that's what I've gone back to.

I know it's a sickening feeling when perfectly good prints turn brown. Good luck solving your problem.

[jose angel]

Yes, I tend to think it was a bad fixing&washing procedure. I also think the KRST "never" go bad.

Mike, the fixer dilution was 1+4, too. I think the KRST is 1:19, not sure. The fixer may be good (I actually don`t take control of the number of sheets, but I think it was not so used), but the short rinse could be the culprit. At that time I hadn`t any Hypo Clearing Agent at hand, so probably it was a too much brief rinse. There must be fixer still on the fiber base.

BTW, I have been looking at "The Toning Book", searching for the topic, and it was mentioned the staining problem with Se toners, due to poor fixing and washing process. But I wonder if it can be considered "staining"... there are not marks or spots. Just a yellowish base, specially at the emulsion side.

I don`t want to reprint the same pic again... argh! Too much stuff to print. And with burnings&dodgings... I`ll try to refix and to wash using HCA, hope it works. If not, I`ll have to make a new print.

Thank you all very much.

[IanG]

It's residual silver left in the paper causing the staining, it's a mix of silver/thiousulphite complexes that aren't fully soluble. Fixing is a complex sequence of equilibrium reactions and if the fixing bath is part used some of these complexes form weak bonds with the cellulose in the fibre based paper so won't wash out, with selenium toning you get a yellow stain.

Simplest solution is to use two bath fixing, it actually works out being more economic, the fresher fresh fixer in the second bath with a low silver level completes the equilibrium processes and leaves no insoluble silver/thiosulphate complexes.

It's highly unlikely you'll remove the stain now.

Ian