Washing Out Optical Brighteners

I think we all agree then. 24h is the limit for extended FB print washing.

This leaves the flexibility of leaving prints in the water overnight for further processing. Since 30-60 minutes is a typical wash time for FB prints, I'll stick to my orignal statement that it is difficult to overwash FB prints. I know of nobody who washes prints longer than a day, and if they do, they may have a problem.

Ideally you should test some Warm tone papers like MCC & particularly Ilford Multigrade FB Warmtone where the optical brighteners are quite different.

Those wash times will be more critical and the effects more noticeable and seen within a few hours.

Ian

Photo Engineer said:

Ralph;

I would pose this question from another angle. Although the US uses Chlorinated water, many counties use Ozone to treat water. It would be interesting to know the effect of Ozone vs Chlorine on papers, images and brighteners. These are a few among a lot of other questions that might be asked.

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Ian Grant said:

Ralph, UK water is often treated with Ozone as well as Chlorine, that's common in most of Europe because Chlorine doesn't kill Cryptosporidium. (I've no darkroom in Turkey).

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Here in the Netherlands, where we have one of the best qualities of drinking water anywhere on the globe, ozone is almost always used in combination with activated carbon beds.

Ozone is best used before the activated carbon beds, as these will remove any by-products generated by the breakdown of organic material under the influence of ozone. In this case, if I understand it well, most if not all of the ozone will have been removed from the drinking water even before hitting the road to the client through the water mains. However, sometimes ozone is used as one of the last steps in disinfection of drinking water as well.

More and more, in the newest installations, an UV light disinfection is added as well.

RalphLambrecht said:

In addition, I have four photographs from another test, which spent 10 years behind a south-facing window. The optical brighteners in these papers (also Ilford MGIV) are completely exhausted by now.

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Ralph,

As you state here, the loss of optical brightener with time due to both illumination and attack by aerial pollutants like ozone, is probably a far bigger concern (or not, depends on how you look at it) than washing them out...

Aardenburg Imaging and Archives did a test that showed severe loss of OBs in just 1.5 years under normal keeping conditions, both due to light and presumably ozone from a dehumidifier. See the attached images.

Be careful: the darker blue area around the photo in the second attached image with the full photo visible and window matt lying beneath it, actually represents less optical brightener activity, if I understand it right, while in the other photo with the edge effect due to ozone, the lighter area is not caused by more optical brightener activity, but by full degradation of the OB and yellowing of the paper due to the ozone. The difference between lighter blue fluorescence due to higher remaining OB activity under the removed matt in the first picture, and a yellowed non-fluorescent blue edge in the second due to ozone destroying the OB, is easy to misinterpret...

Full report is here: "A Year in the Life of an Inkjet Print"

And just look at the average offset printed (photo) book, most of them on coated paper stock with OBs, the paper will start to discolour from the edges onwards within a couple of years. I have many examples of these on my book shelves.

Photo paper manufacturers would do better to leave out OBs altogether IMO... as they will die anyway within a timespan of a decade or so, as you also stated

Ian Grant said:

Ideally you should test some Warm tone papers like MCC & particularly Ilford Multigrade FB Warmtone where the optical brighteners are quite different.

Those wash times will be more critical and the effects more noticeable and seen within a few hours.

Ian

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Ian

I've shared my test results, please share yours. I know, you don't have a darkroom where you live now, but you still have your darkroom in the UK, right? OK then, what papers, washed for how long, amount of residual brightener? I like to see your data.

I never claimed for my results to be universal (MGIV-FB only), so, maybe your results can add something to the overall picture, but please share your data.

Marco

Thanks for sharing this. The results match my experience with prints I have on display.

This thread was a response to Ian's objection to my statement in another thread that 'it is hard to overwash FB prints'. I didn't mind doing the test, because I always learn something when I do these things.

Ian's first objection was that optical brighteners would wash out. I tested that for MGIV without much success unless I washed the paper for several days. His second objection was that there will be a bacterial attack of the baryta layer, which I was not able to detect either. The paper staid intact even after 4 days of washing.

So, I think we don't have to worry about optical brighteners washing out or bacteria eating our paper too much, and my statement was correct. It doesn't seem to be too easy to overwash FB prints. However, testing for it with one's favorite materials is never a wate of time. I hope we will some other test results to get a more complete picture.

PE told us that RC papers have locked-in brighteners that are very hard to wash out, David Vestal tested washing for almost a day and got the same results as I did. Ian claims that this will be different with warm-tone papers, and he may be right that these papers are an exception. So, I'm looking forward for him to post his test results, or maybe, he can repeat the test, when he gets back to his darkroom.

All in all though, you brought it back to a reasonable point. We don't need to worry about washing out optical brighteners, because displaying our prints will take care of them anyway. Leaves us with bacteria (not destroyed by UV, ozone or coming in later) to eat our prints within a day. I wonder what they might be, but luckily they don't seem to exist where I live.

RalphLambrecht said:

Ian

Since you make these statements, I must assume that you've tested these papers already. So why do I need to test for it? Just share your results. What papers, washed for how long, amount of residual brightener? I like to see your data.

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I've gone by ilford's statement from their Multigrade Manual that extended washing removes the optical Brighteners in Mutigrade FB Warmtone. Also practical experience with older Ilford papers, Agfa MCC & Record Rapid, Polywarmtone etc.

"All Multigrade papers, except Multigrade FB Warmtone, have anchored optical brighteners which means they won’t wash out and the paper stays white. With Multigrade FB Warmtone, the brighteners can be removed with extended washing for an even warmer base tint."

I tend to wash for an hour after a 2% Sulphite bath if I've no time for toning, then dry the prints. Then later after Selenium toning and a rinse followed by a a Sulphite bath, I wash for a further hour. I prefer to Selenium tone in daylight.

When I've time & it's still daylight I wash for 30 mins after fixing, selenium tone, rinse and the 2&b sulphite followed by an hours wash.

Personally I don't want to wash out the optical brighteners and it only happens when I leave prints soaking overnight, which would be about 8-9 hours, and I stopped doing this because I didn't want it happening

At the moment I'm still mainly using Forte Polywarmtone, and have enough to last another year, but testing and passing on the results would be pointless as it's no longer available. When Mirko (Fotoimpex) resumes production it'll most likely be on a different base.

I don't use Multigrade FB Warmtone which is where Ilford actually state you can deliberately wash out the brighteners to get a warmer looking base. So someone else would need to test the paper.

It's recommended not to over extend washing in Kodak's old datasheets due to physical deterioration of the images, Ilford say the same.

Not all papers are the same as Multigrade IV FB so it's wrong to assume data is similar for other papers as Ilford themselves point out in the Multigrade manual.

Ian

Ian

Thanks for clarifying this. So washing out optical brighteners is not your experience either, but you are concerned about it due to Ilford's statement in their Multigrade manual. That's reasonable, it would make me at least suspicious about it too. The good thing is, it seems to be limited to warm-tone papers if it happens at all. We will need to test this paper or ask Ilford to verify.

Some general points here are in order.

Optical brighteners act by energy transfer. They absorb high energy UV and produce blue light which has lower energy. Gradually, brighteners fade and leave a dull mud colored residue which no longer brightens but instead degrades the image.

Optical brighteners turn an image blue from a true black and therefore can interfere with warm toned images. It is thus desirable to have the option of removing brighteners for a truer warm tone.

Ozone in water, if removed, allows bacterial and mold growth in the delivery lines to the home or industry and therefore it is desirable to add a small amount of Ozone or other bacteriostat to the water before entering the water main. AFAIK, all treatment plants that remove organics with charcoal also recharge the water with such bacteriostats as are known to be useful but which don't pose a great health risk. This is usually Ozone again or Chlorine. A pH adjust is also made.

It is possible to overwash paper. Ctein has shown that a tiny fraction of Sulfur residue is useful in preserving prints. His work has been published and the keeping tests show that this tiny residue of Sulfur effectively protects images from premature fade.

PE

RalphLambrecht said:

Ian

Thanks for clarifying this. So washing out optical brighteners is not your experience either, but you are concerned about it due to Ilford's statement in their Multigrade manual. That's reasonable, it would make me at least suspicious about it too. The good thing is, it seems to be limited to warm-tone papers if it happens at all. We will need to test this paper or ask Ilford to verify.

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You missed where I've said a few times in my last post and earlier in this thread and before that I have practical experience of optical brighteners being washed out but that I only use warm tone papers. Ilford changed the optical brighteners in Multigrade IV FB, they washed out of the earlier version which I used.

Except for deliberately washing the Brighteners of certain papers there's no benefits at all from over washing, and goes against the manufacturers advice.

Kodak state "Avoid prolonged washing and soaking times to minimize physical damage to the prints." and the same here. Dave Butcher (formerly of Ilford & still one of their Master Printers) says the same, and I posted the link earlier in the thread.

In addition George Eastman House, International Museum of Photography and Film, and the Image Permanence Institute, Rochester Institute of Technology published a document stating the same.

Ian

Photo Engineer said:

... It is possible to overwash paper. Ctein has shown that a tiny fraction of Sulfur residue is useful in preserving prints. His work has been published and the keeping tests show that this tiny residue of Sulfur effectively protects images from premature fade.

PE

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PE

Fully agree, that's why I'm a big fan of direct polysulfide toning. There is no lack of sulfur after that, and at that point, doing damage through 'reasonable' overwashing is hard to do. With 'reasonable' I'm referring to an hour or two, and if need be, leaving the print in a bucket overnight for further processing the next day.

The alternative (not fully washed but dried for later processing), as was suggested in another thread, is not advisable, because dried thiosulfate is close to impossible to get out of the print.

That's the only point I wanted to get across. The danger of washing out brighteners or any bacteria attack seem minor to me in comparison to not toning or underwashing due to a lack of available processing time.

My advise is: If it's getting late and you have to get up the next morning, throw them into a bucket and don't worry about it too much. That's a lot better than not toning or skimping on the wash.

Do you agree?

Ian Grant said:

... Except for deliberately washing the Brighteners of certain papers there's no benefits at all from over washing, and goes against the manufacturers advice. ...

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For Pete's sake, Ian.

Nobody is proposing overwashing, but there is no harm done by leaving the print in a bucket overnight and then continue with toning the next day if that helps to be at work on time and not get fired. Forget your optical brighteners, they'll be gone eventually anyway and one should not rely on them for print quality either. And, you are grasping at straws with your bacteria-attack theory for an overnight soak.

Very sound advice Ralph and very practical as well.

My sessions run from 4 - 8 hours. During that time, I can produce up to 40 8x10 prints. I hold them all in a huge tray of still water and then at the end of the session, I wash them all for the recommended time, in running water in that same large tray.

PE

RalphLambrecht said:

For Pete's sake, Ian.

Nobody is proposing overwashing, but there is no harm done by leaving the print in a bucket overnight and then continue with toning the next day if that helps to be at work on time and not get fired. Forget your optical brighteners, they'll be gone eventually anyway and one should not rely on them for print quality either. And, you are grasping at straws with your bacteria-attack theory for an overnight soak.

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You move the goal posts, it was 24hrs, now it's over night

My take is that overnight washing may be OK but I prefer whenever possible not to, over 24 hrs even less so, based on the visual assessment of prints I've made.

As to whether there's any harm with a prolonged wash such as an over night wash or soak the experts at the Image Permanence Institute (Rochester Institute of Technology), Kodak, Ilford, Ctein etc all seem to think so. My own observations make me think it's not ideal, so I have to agree with their findings.

While the papers I've used often contain optical brighteners that may wash out I'm actually more concerned about consistency in exhibition sets.

The important point is that not all papers use anchored optical brighteners, and some are poorly hardened, so what's fine for one paper, like Multigrade FB IV, may be wrong for a another paper like Multigrade Warmtone FB, or MCC, Polywarmtone etc.

References to bacteria were for 24 hrs and over (in northern climates) and low water temperatures. You had two others say the same as me though about that in this thread.


Maybe the other issue is whether you are processing for archival permanence. If you are then over washing will negate your earlier efforts, if you're not then it's not so important. But this does need to be taken into account.

Ian

Since reading the research published about the protective effects of sulphide, I have taken to adding a few drops -from an old Tetenal toning kit,to my working strength KRST.
Can anyone fault this as a working method?

Ian

Thanks for contributing your point of view to this thread.