Trouble with peeling (?) coating in MGFB Cooltone

During the last few days I made a relatively large number of prints on Ilford Multigrade FB Cooltone. This was my first try with Cooltone, but I've many years experience of MGFB Classic, and its predecessor. All prints were air dried on screens.

A few hours ago I was about to start flattening all the dry prints from the previous days work in a mounting press. As a routine, I always check that the prints are completely free from particles, which will otherwise damage the surface. This was when I noticed that in some (about 25%) of the prints there were one or several small (ca 2 mm), approximately rectanglar areas reflecting a greenish-purple sheen. These imperfections were not visible unless looking at the prints from an angle.

I tried to resoak one of the prints in hope that the sheen was from some water soluble substance, but as soon as I removed the print from the bath and let the water run off I could tell there were small "swollen" areas in the same places where I saw the reflections in the dry print earlier. My guess is that the coating is damaged in some way.

These prints had a total rinsing time of two hours or less (presoak before selenim toning and final rinse of one hour). Temperature during rinsing was 20-22C. Besides, they were treated exactly the same as I have treated my MGFB (Classic) prints earlier.

Any suggestion what has caused this? Help very much appreciated!

There are people at Ilford who will be happy to answer your question

https://www.ilfordphoto.com/contact-form/

Harman Tech Service do have a presence on here - you could also "Start a Conversation" with them through the Inbox link at the top right.

I have had paper base problems twice in 35 years of printing that were determined to be from something getting on the roller when the paper was manufactured, creating dimples in the paper that appeared as bubbles in finished prints. Once with Agfa Portrigia and once with Oriental Seagull.

I've seen peeling (and cracking/ crazing of the baryta base) on several different brands of FB paper, but only after extensive exposure to certain alkaline substances - sulfide toners in particular. There may be something in your specific process which is causing this or other emulsion swelling problems - carefully document what came in contact with your paper & for how long - & speak with the Harman tech support people. Excessive periods of washing (possibly in water of unknown pH) can cause all manner of problems.

OK, Thanks.
I will contact Ilford.

I have seen flaking of the emulsion layer on Art 300 many times, I have not seen this on the other Ilford Paper .

About 5% of my Cooltone sheets have had little zits or coating voids on them the size you relate. They didn't peel, so I could have retouched them with spotting dye;
but it was easier just to reprint.

Update. I have been in contact with Harman Tech Service as suggested, and they were very helpful.

I first sent images of the phenomenon (also enclosed here, description below) and waslater asked to send them prints. In a final conclusion they believed that "the defects to be debris which has landed on the paper during the washing stage - as development has not been inhibited. A thin film has landed on the paper surface, which has proved difficult to remove. Its unlikely just re-washing prints would remove it."

Since they are professionals I respect their conclusion. But as I wrote to them it seems very unlikely to me that this is due to something sticking to the prints. Firstly, I don't see why it shouldn't it be possible to remove by re-rinsing. Secondly, I've used the same procedure for more than decades, the only change is that I changed to Cooltone from Classic, and have never observed the effect before. These are my unprofessional beliefs of course. In a recent printing session I have only dared to use Classic paper. I will now use Classic paper and Cooltone papers remaining from the "bad" box in parallel - this should give a definite answer to the causes.

Enclosed images: Same part of damaged print photographed straight on (above) and with light reflected from the surface (below). Several prints had 2-10 damages of this type, all of them a few mm long.

Update:
I did not see any similar problems with the cooltone papers I kindly was sent by Harman Tech Service. And when I again tried papers from my own "bad" box (which I long hesitated) I did not have any problems with them either.
So I don't know what happened the first time (still doubt it had anything to do with a substance sticking to the surface). I will continue to use Ilford Cooltone FB papers.

Finally, I think I have a solution to the problems described above. I post my mail correspondance to Harman Tech Service below in case someone approach a similar problem.

"Dear X,
I realize I never came back to you and thanked for the fiber based papers you sent. Thank you very much!

After six more months I think I finally have an explanation for the irritating phenomena on the prints (the green/coloured defects seen when light is reflected in a dried print).

Already in December I could conclude that there was nothing wrong with the papers: First of all I didn't have any problems with the papers I received from you, and when I later went back to the pack that I had suggested was damaged I didn't have any problem with those papers either. Good news, but I still didn't have any explanation for the problems earlier.

One week ago the problems returned, but now I think I know how to avoid them.

Since more than twenty years I always selenium treat my prints MGFB to get deeper blacks (as you know one don't get a very strong effect on MGFB but there is an increase in contrast which is attractive). Before the printing sessions last winter when all went well I had made a new stock of 10% Kodak selenium toner. Since selenium is environmentally unfriendly (I leave it for destruction of course) I always try to use it as long as possible.

When the solution has been standing for a couple of months or so a precipitate (Selenium crystals of some kind?) form and collect at the bottom. I think what may have happened is that some crystals stuck to the surface of prints and cause the phenomenon seen. If I decant the selenium toner to avoid the precipitate it seems as if I can avoid the problems. I still don't understand why the crystals would keep sticking to the surface following HCA treatment and 1 hour wash, or why they can't be removed be rewashing. And I don't understand why I didn't observe this phenomenon before. But it doesn't matter as long as the procedure work, and right now the selenium toner is the most likely candidate to the earlier problems..

Best Regards,

PerA"

PerA,

FWIW, I've been replenishing and reusing selenium toners for years now and never have had the problem you refer to. I do filter the toning solution before and after each toning session. When the toning times become uncomfortably long, I add a bit of concentrate to bring the toner back up to speed. That's it: filter, replenish, reuse indefinitely.

Best,

Doremus

That doesn't help the real mfg issue I've sometimes had with both Cooltone and Fineprint VC before that - little blank white freckles as if nothing was even there. I've had suspicions that it's related to packaging, with something unwanted getting onto the paper, since it seems to afflict sheets near either the top or bottom of the stack in the box. I hope that's cured; but it won't stop me from buying more Cooltone. It fills an important niche.

Doremus Scudder said:

PerA,

FWIW, I've been replenishing and reusing selenium toners for years now and never have had the problem you refer to. I do filter the toning solution before and after each toning session. When the toning times become uncomfortably long, I add a bit of concentrate to bring the toner back up to speed. That's it: filter, replenish, reuse indefinitely.

Best,

Doremus

Click to expand...

DREW WILEY said:

That doesn't help the real mfg issue I've sometimes had with both Cooltone and Fineprint VC before that - little blank white freckles as if nothing was even there. I've had suspicions that it's related to packaging, with something unwanted getting onto the paper, since it seems to afflict sheets near either the top or bottom of the stack in the box. I hope that's cured; but it won't stop me from buying more Cooltone. It fills an important niche.

Click to expand...

Doremus,
If the cause of the problems is as I now suspect - crystals sticking to the surface - filtering should work equally well or better than decanting.
Best, PerA

This is not a new problem but one that is over a decade old. I have IDK 5 100 sheet boxes of Ilford mg paper where the emulsion flakes off the edges of the paper. No toning involved just dev, fix, wash, perma wash, final wash. This has been a problem since before 10 years ago; and it was like this as soon as I used it, first sheet, and every sheet in the box since. I brought this problem to the attention of the local shoppe I purchased it from, and was referred to the good folks at Ilford and ( I think I even exchanged messages with Simon G ) then I sent scans to their local trouble shooting rep here in the states. I was not really given an explanation other than shrugged shoulders and told to trim the edges off all my prints. Looks like the problem still persists. Good luck with your situation !
John