Sepia Toners

RalphLambrecht said:

....... Also, keep in mind that thiourea does not give the strong archival protection, which sulfides do.

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I have just had a quick look into the Tim Rudman Toning Book, and he seems to group all sulphide toners (including thiocarbamide) together as "recommended archival treatments." Which of course is not to say that there aren't some differences between them. I had been under the impression that sulphide and thiocarbamide were just two different ways to get to the same place (silver sulphide).

The polysulphide treatment is often cited as particularly effective archivally.

There would appear to be a difference of opinion or is it fact on whether thiocarbamide adversely affects unexposed paper in terms of fogging. Tim Rudman clearly comes out in favour of thiocarbamide both in terms of smell( lack of) and fogging (lack of) compared to sulphide toners.

Reading his book Tim would appear to believe that sulphide toners create a considerable smell although others here report that the smell isn't that bad. However for me the bigger worry is paper fogging. It would appear that I can either believe an apparent authority on toning, namely Tim Rudman or accept that he has got it wrong and thiocarbamide does fog paper.

Can I ask if those who believe that thiocarbamide fogs paper are repeating the views of others or indeed have experienced fogging of paper when using thiocarbamide

It would be nice if we can establish beyond reasonable doubt the guilt of thiocarbamide in terms of fogging unexposed paper. For this purpose and for reliable answers, lets assume: 1. that the paper is in the same room but has been wrapped on its blackbag,is still in its box and in a cupboard 2. the paper is in a papersafe on the dryside shelf so not in a cupbaord,is protected from light but doesn't have a blackbag nor the orginal tight fitting cardboard box.

Thanks

pentaxuser

pentaxuser

john_s said:

I have just had a quick look into the Tim Rudman Toning Book, and he seems to group all sulphide toners (including thiocarbamide) together as "recommended archival treatments."...

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Tim Rudman is correct. Thiourea is a good indirect toner, but as a direct toner, it is not as 'archival' as polysulfide.

Also, see Tim's book on page 96:
'FSA (aka thiourea dioxide) is not an archival toner.'

john_s said:

...The polysulphide treatment is often cited as particularly effective archivally...

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No doubt about that!

Stefan Findel said:

Clayne, you may have very hard tap water. Here is what I do: Use distilled or filtered (Brita filter) water to make toner. After toning, place print for one minute in water, then for 15 seconds in a 1% acidic solution (stop bath), then wash as usual. That should take care of any white deposits.

BTW: I never use distilled water when called for, I find Brita-filtered water to work fine.

Stefan

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Stefan the problem is that I don't think I have hard tap water. In fact according to a water hardness test it's quite soft. I've considered in the past that it was due to hardness and calcite deposits - but it seems that it's hit and miss as to whether this residue appears. I've heard that dunking chalky prints into stop-bath is an easy way to get rid of it - but i usually just brush it off under running water and rewash. My steps are usually toner->rinse->hca->wash(30)->dry.

Reason I use distilled water is because the dehumidifier produces it and it's quite decent water to use for toning, etc. The small amounts of dust in it don't present an issue.

Tim Rudman is correct. Thiourea is a good indirect toner, but as a direct toner, it is not as 'archival' as polysulfide.

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Ralph, does this mean that what you said in (there was a url link here which no longer exists) above only applies to direct toners? Should indirect thiourea toners be fine as far as the archival protection is concerned?

Clayne, I don't think hard water is the culprit. I have mixed my sodium sulfide solution with distilled water, and now, four days and a few prints later, it already has some sludge on the bottom.

Speaking of pH, my 1% sodium sulfide solution (ca. 0.13M) has a pH of approximately 14. I'm saying "approximately" because I'm using some cheap indicator paper stripes, and not a professional, well-calibrated pH-meter. But the paper shows a definite 14.
So, a pH of about 14 for Viradon seems correct to me.

VladSoare said:

Clayne, I don't think hard water is the culprit. I have mixed my sodium sulfide solution with distilled water, and now, four days and a few prints later, it already has some sludge on the bottom.

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Vlad, this is different - we're talking about light white chalky residue on dried prints. It's a quite common Viradon after-effect. It's not the end of the world and comes off, but it's still a hassle at times.

Oh, I see. My mistake.

VladSoare said:

Ralph, does this mean that what you said in (there was a url link here which no longer exists) above only applies to direct toners? Should indirect thiourea toners be fine as far as the archival protection is concerned?

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Vlad, I think one of the main issues with all this is, that there is hardly any real scientific research on this topic of toners and archivability, if at all.

I have the feeling that most of it is "hear-say"... I am not saying Tim isn't an authority on toning, and I still need to get his book!, but I do think most of the claims are more based on gut feeling, than real research.

For example, does anybody know here of a controlled scientific study having been published (and hopefully available on the net, as I would like to read it than), where for example differently toned prints (thiourea, sulfide, polysulfide, selenium, copper etc.) of the same image on the same paper are being exposed to controlled levels of "air pollutants" in a kind of accelerated life time test like is done for color photos being exposed to controlled light sources to determine the rate of "fading"???

Marco

By the way, two good resources on (photographic) conservation, although even these seem to lack the kind of research links I referred to above;

George Eastman House:
http://notesonphotographs.eastmanhouse.org/index.php?title=Category:Process_Related_Deterioration

and:
http://www.arp-geh.org/indexsep.aspx?nodeidp=9

Canadian Conservation Institute:
http://www.cci-icc.gc.ca/crc/articles/mcpm/index-eng.aspx#

Especially nice this PDF by Gawain Weaver and well worth reading, a link from the George Eastman House site:
http://www.arp-geh.org/FileUpload_demo/Weaver_Guide_to_Gelatin_Silver_v1.pdf

Marco

VladSoare said:

Ralph, does this mean that what you said in (there was a url link here which no longer exists) above only applies to direct toners? Should indirect thiourea toners be fine as far as the archival protection is concerned?...

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As far as I know, yes. Sorry if I was not clear enough.

Marco

Thanks for those links.

I'll take a look and see what I have (and can be shared) as far as scientific studies goes. I was given some instructions from Ilford on how to conduct accelerated ozone tests. The setup is not too difficult. I built all the equipment required and did a few tests comparing no toning to selenium and sulfide toning, but they are probably not as scientific as you'd like to see them.

RalphLambrecht said:

Marco

Thanks for those links.

I'll take a look and see what I have (and can be shared) as far as scientific studies goes. I was given some instructions from Ilford on how to conduct accelerated ozone tests. The setup is not too difficult. I built all the equipment required and did a few tests comparing no toning to selenium and sulfide toning, but they are probably not as scientific as you'd like to see them.

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Well Ralph, it is at least a more or less "controlled" and true experiment you did, instead of just the usual hear-say. So yes, if you can share any results, it would be a nice start for all of us here on APUG to at least get some idea of the protective characteristics of different tonings...

Actually, I think you are to be applauded for being so rigorous on this and your darkroom techniques in general as an individual. I would have expected the research departments of universities, photo companies or museums to do this kind of thing, not an individual photographer.

If Ilford or some other company or organization did this kind of thing too, so accelerated test using ozone or other potentially harmful air pollutants, and anyone has references or interesting links to results of them, I definitely would like to hear about it...

Marco B said:

...I would have expected the research departments of universities, photo companies or museums to do this kind of thing, not an individual photographer.

If Ilford or some other company or organization did this kind of thing too, so accelerated test using ozone or other potentially harmful air pollutants, and anyone has references or interesting links to results of them, I definitely would like to hear about it...

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Marco

Check the web for 'Wilhelm Imaging Research'. They are the best I know of. Unfortunately, they are more concerned about color and inkjet media than silver-gelatin these days.

My ozone tests are by no means a reliable measure of print stability. I use them purely to determine which of two compounds seems to be better at protecting against oxidation. That's not enough.

From the instant of its creation, a silver-based image faces attack from a variety of sources. Some are internal and essential to the materials, photographic papers are designed and manufactured with. Intrinsic sources can be minimized by proper print processing.

Others sources of attack are of external origin. These extrinsic sources of image attack are hiding patiently in our environment, ready to start their destructive work as soon as the print is processed and dry. They can broadly be separated into reducing and oxidizing agents.

Roughly until the introduction of the automobile, reducing agents were the most common sources of image deterioration. Then, oxidizing agents like aldehyde, peroxide and ozone took over. Their presence peaked in the Western World around 1990, and fortunately, began to decline since. Nevertheless, oxidation is my biggest concern.

I was given some instructions from Ilford on how to conduct accelerated ozone tests. The setup is not too difficult. I built all the equipment required and did a few tests comparing no toning to selenium and sulfide toning, but they are probably not as scientific as you'd like to see them.

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That sounds very interesting. Could you please share some details? I'd like to try it myself if it's not too difficult.

RalphLambrecht said:

Check the web for 'Wilhelm Imaging Research'. They are the best I know of. Unfortunately, they are more concerned about color and inkjet media than silver-gelatin these days.

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Ralph, I am aware of Wilhelm Imaging Research. But like you say, they are more involved in light induced image fading of color materials... I even downloaded and printed one of these huge PDF documents relating to analog photography, but the word "silver gelatine print" is hardly there, except for some references to old B&W RC prints and issues of fading. Fair enough, the title already stated it was about color photography ("The Permanence and Care of Color Photographs")

I guess this has to a large extent to do with the far more easy test-up. Just measure the light hitting your test prints (now ignoring all other factors for simplicity), and you are done.

Far easier than building a controlled test setup for gaseous induced (whether oxidizing or reducing) degradation of the images.

VladSoare said:

That sounds very interesting. Could you please share some details? I'd like to try it myself if it's not too difficult.

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You need to build an air-tight glass chamber (fish tank), large enough to hold several test prints, a small container for liquid chemicals and a small battery-driven fan (computer fan). Fill the container with hydrogen peroxide (make sure to read safety instructions), close the tank and with the fan running, create an environment of 1,000 - 2,000 ppm of gaseous hydrogen peroxide.

Run the test until you observe severe fading of an unprotected print, and compare it to protected prints.

A simpler test is to mix a 1% potassium ferricyanide solution (bleach) with paper-strength fixer and see how well a toned print compared to an untoned print does in it.

OK, I now noticed in "Further reading" list in the PDF article of Gawain Weaver that I linked before, that there is a reference to a study of different toning treatments to attack of peroxide gas. Is there somenone who could dig this up in the US? Or someone who happens to have it in his personal photography related library?

The reference is:

Gmuender, C. (1992). On black-and-white paper image-stability enhancement effectiveness of toning treatments on silver gelatin prints determined by the hydrogen peroxide fuming test (M.F.A. Thesis, Rochester Institute of Technology, 1992).

Marco

Well, as usual, one thing leads to another, here some other interesting stuff, including another reference to the same thesis / study I just mentioned, that seems to be a hefty 411 page document according to the last sentences in the Large Format forum link:

http://www.largeformatphotography.info/toning-permanence.html

And also interesting for Vlad concerning the hydrogen peroxide tests:

http://cool.conservation-us.org/byorg/abbey/an/an12/an12-5/an12-507.html

Marco

Try this link: linky link

If you can't access that directly, let me know.

Tim Gray said:

Try this link: linky link

If you can't access that directly, let me know.

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Thank you so much! , bookmarked the RIT Digital Media Library as well.

Ohohoh, it's a huge read from a quick glance on it, but something like this I have been wanting to see for a long time! Great, with some of the basics of the chemistry of the tonings in there as well!

In addition to the Gmuender's work there is another thesis work made by Istvan Kecskemeti in Denmark in early nineteens. He tested different the effect of different toning processe according to the ANSI IT9,15-1992 standard "The effectiveness of chemical conversion of silver images against oxidation - methods of measuring. In the study he exposed differently toned grayscale prints to dichromate bleach and hydrogen peroxide gas, like Ralph described, and measured the changes in different tones.

I have the thesis somewhere here but was not able to locate it right now, so I can not give the exact reference or further details until I find it. I'll return when I have more to say.

Olli

You need to build an air-tight glass chamber (fish tank), large enough to hold several test prints, a small container for liquid chemicals and a small battery-driven fan (computer fan). Fill the container with hydrogen peroxide (make sure to read safety instructions), close the tank and with the fan running, create an environment of 1,000 - 2,000 ppm of gaseous hydrogen peroxide.

Run the test until you observe severe fading of an unprotected print, and compare it to protected prints.

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Thanks Ralph, that sounds easy enough. I think I'll try it sometime.

A simpler test is to mix a 1% potassium ferricyanide solution (bleach) with paper-strength fixer and see how well a toned print compared to an untoned print does in it.

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Well, I'm sure a ferricyanide bath attacks metallic silver (after all, that's exactly what we're using it for) and doesn't attack silver sulfide or silver selenide, so I more or less know the outcome of this test even without doing it.
But in practice ferricyanide is probably the last thing a framed and displayed print will come in contact with.

What I am suspecting, but I haven't actually seen this confirmed in articles, is that the heightening of the pH in a bleach / redevelop thiourea (or sulfide toner), actually causes more of the formed silver / ferri/ferrocyanide complex to be broken down and also converted to Ag2S.
[............]
It thus may explain the more yellowish tones of a plain thiourea redeveloper, without added NaOH, as the substance remains partly in the final toned print, while heightening the pH using NaOH, may help in converting it to Ag2S as well.

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Marco, I wonder whether this has also to do with the willingness of thiourea and sodium sulfide to release sulfide ions. It could be that the double covalent bond between the sulfur and carbon atoms in thiourea is stronger than the ionic bond between sodium and sulfide ions in sodium sulfide. So while sodium sulfide is happy to release its sulfide ions in an aqueous solution, thiourea may need a strongly basic environment for that. I'm not exactly sure what happens at so low a level, but I think an explanation may be that the carbon atom in thiourea, in order to break its bonds to the sulfur atom and release it as a sulfide ion, needs two hydroxide ions to replace it with. Thus a higher pH (meaning a higher concentration of hydroxide ions) might allow thiourea to release more sulfide ions. But then, I'm not a chemist, so my reasoning could be entirely wrong.

If this were true, then it wouldn't contradict your theory, but would actually confirm it - less sulfide ions released means less of the ferrocyanide/bromide complex converted to silver sulfide, and more of the yellowish compounds left unconverted in the print.

However, looking at the thiourea toner formula shown here, I see something interesting. The more potassium bromide in the bleach bath, the warmer the tone of the resulting image. Jack says there that using 25g instead of 50g of potassium bromide yields cooler tones, and the second bleach bath described there, made specifically for cold tones, has no bromide at all. So, if what he states there is true, then the higher the silver bromide to silver ferrocyanide ratio is, the warmer the tones will be.
Now I'm confused... :confused:

Wow! Great news!
Toning book reprint

So, can a thiourea toner be used in the same room where I keep unexposed photo paper and sheet film? It would be nice to know once and for all.

I bought some thiourea toner with the thought that I can use it in my darkroom, instead of smelly toners that fogs my films and papers.

As long as there's reasonable ventilation, it doesn't give of fumes like Sulphide toners so there's less risks of fogging stored unexposed papers.

Ian