Wait... so selenium toning does not improve archival properties?

[hoffy]

Selenium toning is archival if done fully. Sulphide toning provides good protection even if done briefly as Ina minute or two!

Hi Ralph,

Do you cover off Sulphide toning in your book?

 

[Gerald C Koch]

Only with indirect toning and a bleach stage, you won't see that with direct toning.

I get a very nice chocolate brown using a direct liver of sulfur based toner. No indirect toning required.

 

[Ian Grant]

I get a very nice chocolate brown using a direct liver of sulfur based toner. No indirect toning required.

Yes you will,, however the answer to Bill Burk was regarding a 0.1% Sodium Sulphide solution and we are talking about a short time. Liver of sulphur toner is typically a 1.75% solution and needs a higher temperature.

Liver of Sulphur is a poorly defined mixture of potassium sulphide, potassium polysulphide, potassium thiosulphate, and probably potassium bisulphide, so quite different to Sodium Sulphide.

So in the case in question with Sodium Sulphide we are talking about an 1/8 of the time, 1/17.5 the dilution, just these two parameters alone give a factor of 140x, that's leaving out the effects of the elevated temperature needed with Polysulphide toners and the fact that Liver of Sulphide and sodium Sulphide don't work quite the same way. in toners.

Ian

 

[RalphLambrecht]

I think a search on "Douglas W. Nishimura" will give you good reading about how vulnerable our silver images are...

Here's an example article, seems very plain to me. Selenium Toning isn't going to protect your silver from red spots.

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

I agree, this is a great article and very clear.

 

[Ian Grant]

I'm intrigued by this paragraph in the article I posted:

Sulfiding Treatments
...only a small amount of the sulfiding agent is needed. For example, sodium sulfide solutions of 0.1 grams per liter... are completely effective.

It must be Sodium Sulphide as highly dilute Polysulphide works much faster than expected and can stain highlights.

Ian are you suggesting that going to .1% solution I can tone without change and there will be protection, even though no visible change.. this is new and interesting concept as when I do sepia selenium I on Ilford warmtone the prints go warmer than I would like -

Well with a 1% Sodium Sulphide and a short bath there should be sufficient toning to protect the silver without causing a noticeable change, the last time I did this was over 30 years ago and not with Warmtone paper. It maybe you'd need to go to a 0.5% Solution, it's worth doing some tests.

If you want to stop Sodium Sulphide toning then a Sodium Bicarbonate solution should work, it's used to neutralise Sodium Sulphide spills and accidental discharges.

Ian

 

[john_s]

Just to clarify, a solution of sodium sulphide without any other ingredients will give the desired permanence effect with no (or very minimal) colour shift? It seems too easy to be true.

 

[Ian Grant]

Just to clarify, a solution of sodium sulphide without any other ingredients will give the desired permanence effect with no (or very minimal) colour shift? It seems too easy to be true.

It's long been known that a very brief bath in dilute Sodium Sulphide solution greatly improves archival permanence, it offers protection of the silver from atmospheric pollutants causing oxidation. However work done as far back as the 1920's, by Lumiere and Seyewetz in 1923 indicate there can be yellow staining problems with residual fixer complexes if the fixer bath contains more than 2 g/litre Silver, this can be worse with higher dilution of the Sulphide solution.

Kodak research by K. Hickman and D. A. Spencer, 1922, indicated that a trace of residual hypo 0.00016g per 100 sq cm has no detrimental effects on image permanence and that mirrors PE's comment about Ctein and image fading with over washing. What we are looking for is controlled oxidation of the surface of the silver grains that offers improved protection. which is the principal of Agfa's Sistan.

Most people don't want to use Sodium Sulphide on a regular basis in their darkrooms, which is the main reason it's not done.

Ian

 

[Ian Grant]

Just to clarify, a solution of sodium sulphide without any other ingredients will give the desired permanence effect with no (or very minimal) colour shift? It seems too easy to be true.

Ok an update, I made up a 1% sodium Sulpide solution, then diluted 30ml to 300ml so a 0.1% solution.

I cut 3 prints in half placing the left hand side in the Sulphide @ 20ºC first two were for 2 mins the 3rd for 5, none exhit any colour or density shift in the image or base.

To test what's happened the second print (both halves) was placed in a 1% Ferricyanide/Bromide re-halogenating bleach for 2 minutes. The left hand side has only bleached very slightly, the right hand side all highlights and mid tones have bleached the, just the deep shadows are left.

The 2 minutes in 0.1% Sodium Sulphide has very significantly protected the image with no ill effects at all in terms of density, colour, staining, the paper was some old Kodak Polymax RC. Obvoiusly the longer it's left in the solution the greater the protection and there's some room to experiment with longer times and/or a stronger solution.

I left half a 4th print in the Sulphide solution for 30 minutes and there is a colour shift the left looks warmer toned there's maybe a just detectable drop in highlight density. As the effects will differ with other papers particularly Warmtone papers you'd need to do your own testing.

I have done this once before (over 30 years ago)and it was near impossible to bleach the image, I would have used Part B from Ilford IT-1 toner which is a 5% Sodium Sulphide solution diluted 1+9 for use so a 0.5% working solution.

Ian

 

[john_s]

Thank you Ian. I plan to do this from now on. It does seem important to make sure that fixer is not overused. I use two bath fixing so I should be ok.

 

[hoffy]

How does sodium sulpide toning fit into the general process? Is it required to be done after the wash? How much washing is required either side of the process?

 

[Ian Grant]

It depends whether you are using RC or FB papers. My normal sequence for FB papers would be 2 bath fixing, wash for 5 mins, 2 mins in HCA (in my case Sodium Sulphite soln) wash 20 mins, Selenium, tone, then a final wash 30 of mins. adding a Sodium Sulphide bath I'd wash for 10 mins after the Selenium toner then the Sodium Sulphide bath, followed by the 30 min wash.

As I always make a number of prints in a session I'm building up prints at the first washing stage so when it comes to the subsequent HCA and toning stages I have a reasonable work flow so I'm not sat waiting during wash steps.

I should emphasise that I've not yet determined the optimum immersion time for the FB papers I use, I'm finishing my stocks of Forte Polywarmtone and have a large stock of Ilford Warmtone ready on teh darkroom shelves. The Sodium Sulphide didn't tone anywhere near as fast as I'd have expected, initially in this thread I suggested 1 min in the 0.1% soln as a starting point, so tried 2 mins, then 5mins, now the prints are dry I'd be happy with the 5 mins. No discernible colour shift.

If I can find some scrap Warmtone prints I'll do some more tests, I tend to keep odd test strips etc for testing.

Ian

 

[RalphLambrecht]

Hi Ralph,

Do you cover off Sulphide toning in your book?

Yes, under archival processing!

 

[warden]

Yes, under archival processing!

Sorry for the thread hijack but I was just thumbing through your book to brush up on split grade printing before starting a mini project and it was very helpful to me. Thanks! I'll check out the toning section as well.

 

[Bill Burk]

I think at the low concentration being considered (0.1% Sodium Sulfide) the risk might not be high, but an old "Chemistry of Photography" (Mallinckrodt Chemical Works 1940) book cautions ... Sulfur vapors ... attack and destroy any sensitized material stored in the room.

I'm sure they were talking about 120-degree F baths at higher concentration (for direct toning to completion).

At lower concentration, at normal to low temperatures, I'm not risking wrecking all my paper am I?

 

[Arklatexian]

This whole thread leaves me scratching my head. After all these years of photographers toning in selenium in order to preserve prints, it now seems that this was bogus. Not being a chemist, and having to rely on what I read in (supposedly) reliable books, I find this rather depressing! It makes me wonder what else folks like me have been told (and believed) over the years that is not reliable.

On the plus side, the very first prints I made (in 1970) still look just fine and will no doubt outlast me. They were printed on Agfa fb paper and washed for half an hour in a basement sink with absolutely no other equipment and no toning at all. So much for archival methods.

You and I have had the same experience when it comes to archival methods. Many of my prints are getting quite old (fifty or so years) and I see little to no change or changes. I have always (after learning to develop prints as far as they can in order to bring out fine details that I had been missing), using stop bath, fixing for ten minutes and washing for 30 to 60 minutes. Quit washing 60 minutes when I started using HCA. Anyhow, how long are we archiving for? 100 years, 1000 years, longer? 100 years is no big deal already with proper fixing and rinsing.....Regards!

 

[Ian Grant]

I think at the low concentration being considered (0.1% Sodium Sulfide) the risk might not be high, but an old "Chemistry of Photography" (Mallinckrodt Chemical Works 1940) book cautions ... Sulfur vapors ... attack and destroy any sensitized material stored in the room.

I'm sure they were talking about 120-degree F baths at higher concentration (for direct toning to completion).

I rarely use Sodium Sulphide as a toner, the previous time was over 30 years ago, I'd make a fume cupboard if I wanted to use it regularly in a darkroom.

However this 0.1% solution of Sodium Sulphide is weak and the sulphide smell is slight, only noticeable a couple of feet above the tray, I used it close to the darkroom door which was open all the time so plenty of circulating fresh air. (My darkroom is a separate building at the end of my garden). The sulphide eruption from my companion who was lying on the darkroom floor was far worse

We can detect the smell of extremely low levels of sulphide, it was something I gave thought to before doing my tests and I was using 300ml of the 0.1% solution a small tray (10x80 at room temperature around 20ºC. If I were to use a sulphide step for archival processing it would be a larger volume in 20x16 trays and would pose a greater risk I'd work outside or make a fume cupboard - it needn't be elaborate as long as there's a good extractor fan and you can't smell the sulphide fumes.

At lower concentration, at normal to low temperatures, I'm not risking wrecking all my paper am I?

It's very unlikely but it's worth erring on the safe side, the danger is when the sulphide smell is obnoxious and becomes intolerable, and is in a confined space with no ventilation, also when the use is frequent.

Ian

 

[RalphLambrecht]

I think at the low concentration being considered (0.1% Sodium Sulfide) the risk might not be high, but an old "Chemistry of Photography" (Mallinckrodt Chemical Works 1940) book cautions ... Sulfur vapors ... attack and destroy any sensitized material stored in the room.

I'm sure they were talking about 120-degree F baths at higher concentration (for direct toning to completion).

At lower concentration, at normal to low temperatures, I'm not risking wrecking all my paper am I?

I'd keep sulfur vapors away from all pho sensitive materials.

 

[John Wiegerink]

I rarely use Sodium Sulphide as a toner, the previous time was over 30 years ago, I'd make a fume cupboard if I wanted to use it regularly in a darkroom.

However this 0.1% solution of Sodium Sulphide is weak and the sulphide smell is slight, only noticeable a couple of feet above the tray, I used it close to the darkroom door which was open all the time so plenty of circulating fresh air. (My darkroom is a separate building at the end of my garden). The sulphide eruption from my companion who was lying on the darkroom floor was far worse

We can detect the smell of extremely low levels of sulphide, it was something I gave thought to before doing my tests and I was using 300ml of the 0.1% solution a small tray (10x80 at room temperature around 20ºC. If I were to use a sulphide step for archival processing it would be a larger volume in 20x16 trays and would pose a greater risk I'd work outside or make a fume cupboard - it needn't be elaborate as long as there's a good extractor fan and you can't smell the sulphide fumes.



It's very unlikely but it's worth erring on the safe side, the danger is when the sulphide smell is obnoxious and becomes intolerable, and is in a confined space with no ventilation, also when the use is frequent.

Ian

Are they (the fumes) any real danger to us humans?

 

[Ian Grant]

Are they (the fumes) any real danger to us humans?

In quantity yes so it's important to keep it away from acids where Hydrogen Sulphide can be formed, at the typical dilution for a toner 0.5% solution (used after a rehalogenating bleach) more unpleasant than dangerous but you don't want prolonged exposure. At 0.1%, which I tested, my Dalmation emits far higher levels of sulphide gas

Like many chemical Sodium Sulphide needs to be used with caution. Gloves/tongs when handling prints in the toner, and good ventilation. Here in Europe by law we have to do COSHH (Control of Substances Hazardous to Health) assessments in the workplace. I ran a laboratory and I had to have a full risk assessment for the individual chemicals and relevant equipment we used along with the necessary safety precautions that need to be taken and any first aid needs or fire hazards. Chemical suppliers are obliged to issue relevant MSDS sheets.

That sounds far worse than it is in practice, it's a case of reading relevant MSDS sheets and then common sense. Sodium Sulphide is dangerous in terms of skin contact as a solid or concentrated solution, we are using a weak solution but care needs to be taken making it up. I would only use it in a fume cupboard or area with excellent extraction so I couldn't smell it as well as using gloves/tongs.

Personally I'm happy using just Selenium toner, I won;t be adding a Sulphide step for my own work flow.

Ian

 

[John Wiegerink]

In quantity yes so it's important to keep it away from acids where Hydrogen Sulphide can be formed, at the typical dilution for a toner 0.5% solution (used after a rehalogenating bleach) more unpleasant than dangerous but you don't want prolonged exposure. At 0.1%, which I tested, my Dalmation emits far higher levels of sulphide gas

Like many chemical Sodium Sulphide needs to be used with caution. Gloves/tongs when handling prints in the toner, and good ventilation. Here in Europe by law we have to do COSHH (Control of Substances Hazardous to Health) assessments in the workplace. I ran a laboratory and I had to have a full risk assessment for the individual chemicals and relevant equipment we used along with the necessary safety precautions that need to be taken and any first aid needs or fire hazards. Chemical suppliers are obliged to issue relevant MSDS sheets.

That sounds far worse than it is in practice, it's a case of reading relevant MSDS sheets and then common sense. Sodium Sulphide is dangerous in terms of skin contact as a solid or concentrated solution, we are using a weak solution but care needs to be taken making it up. I would only use it in a fume cupboard or area with excellent extraction so I couldn't smell it as well as using gloves/tongs.

Personally I'm happy using just Selenium toner, I won;t be adding a Sulphide step for my own work flow.

Ian

OMG, I'm going digital! Just kidding of course, but I do see why some folks might think of going that way if they are deathly afraid of chemicals.

 

[Gerald C Koch]

Carbon dioxide when dissolved in water forms carbonic acid which is acidic enough to release hydrogen sulfide from sulfide solutions. The point being that acid need not be added per se to toner solutions to generate a poisonous gas. In addition hydrogen sulfide will fog film and paper. So it is best not to do toning in the confined space of the darkroom. The release is slow but steady as long as the sulfide toner is exposed in a tray. In low concentrations hydrogen sulfide causes a dull headache ache across the forehead and difficulty in concentrating.

 

[LarsAC]

So don't use sparkling water to make up sulphide toners?

Lars

 

[Bill Burk]

I'm thinking of using it not for tone change, but only for the missing protective effect that (today's KRST) Selenium toner alone is said "not" to provide.

I'm hoping that my new prints can be as archival as the vintage prints toned in previous incarnations of Selenium toner (that had some Sodium Sulfide) which are better protected than my current prints.

I'm not thinking so much as 100 or 1000 years out, as much as I'd just like my prints to make it 30 years without developing red spots.

 

[Gerald C Koch]

The best way to insure archival permanence is still proper washing. It have "drugstore" prints that are over 75 years old that are still in perfect condition. Because of the bottom line I am sure that they were only washed without any special treatment. In addition I have only used washing for my prints.

 

[john_s]

Could a little sodium sulphide be added to KRST to achieve the result of it in its previous version? That would streamline my workflow.