Amonium Thiosulfite vs Sodium Thiosulfate for Salt printing

Mainecoonmaniac · Mar 4, 2012

I just started to my experimenting with salt printing. I really like the process and the look of salt prints. I got a Bostick and Sullivan kit and it came with 250g of Sodium Thiosulfate which I didn't use, but the rapid fix that I already mixed up. I noticed that the rapid fix bleached the print if I fix it too long.

Should I stop being lazy and mix up the Sodium Thiosulfate and use it instead of the rapid fix? Is there a difference between the two fixers?

cliveh · Mar 4, 2012

No, you should use neither. If you follow Talbot's original notes you will see this was not used with his salt prints. As soon as you use fixer with a salt print you destroy the original colour. What you need to do is take a large saucepan of water and bring it to the boil. At the same time you keep pouring in as much salt (NaCl common salt) as will dissolve. What you are making is a super saturation salt solution. When no more dissolves, you let the solution cool. Bottle this and after exposure of your salt print pour this over the image. This will stabilise the salt print, but not fix it (having said this, I and Talbot have noticed that if you get the proportion of salt ratio in balance with the silver nitrate solution coated on the paper, it will be quite permanent, but this is a different story we wont go into here and one I can't do it consistently). You then need to scan it when dry before the image deteriorates.

Jerevan · Mar 4, 2012

Ah, I have to disagree with the above poster.

Use the Sodium Thiosulfate if you want your prints to last. Anything else is just arty-farty reenactment stuff, from the days before Hershels idea to use hypo (Sodium Thiosulfate) to make prints permanent. The Ammonium Thiosulfate will bleach away too much of the print.

Mainecoonmaniac · Mar 4, 2012

That's what I'm finding out! But can I use the rapid fix to control values?

Gadfly_71 · Mar 4, 2012

cliveh said:
No, you should use neither. If you follow Talbot's original notes you will see this was not used with his salt prints. As soon as you use fixer with a salt print you destroy the original colour. What you need to do is take a large saucepan of water and bring it to the boil. At the same time you keep pouring in as much salt (NaCl common salt) as will dissolve. What you are making is a super saturation salt solution. When no more dissolves, you let the solution cool. Bottle this and after exposure of your salt print pour this over the image. This will stabilise the salt print, but not fix it (having said this, I and Talbot have noticed that if you get the proportion of salt ratio in balance with the silver nitrate solution coated on the paper, it will be quite permanent, but this is a different story we wont go into here and one I can't do it consistently). You then need to scan it when dry before the image deteriorates.

This assumes, of course, that you're trying to simulate Fox Talbot's early work. Indeed, he did use NaCL early on but was unhappy with the results (he tried several methods to varying degrees of success). Herschel came up with Hypo (now known as Sodium Thiosulfate) as a means to permanently fix out the excess silver and passed the info on to Talbot (Herschel was very involved with many of the early chemical processes). Both Talbot and Daguerre switched to Hypo when it became clear that sodium chloride was not up to the task.

In answer to the OP. Sodium Thiosulfate is the fixer you want to use. As you've already noticed, Ammonium Thiosulfite is far too active for many of the older processes. Salt prints, Albumens, and VanDykes, all work best with plain Hypo. For VanDykes I use 1 heaping tablespoon of Hypo crystals to 1 quart of water. Works like a champ!

Cheers,
Andrew

Gadfly_71 · Mar 4, 2012

What values are you trying to control exactly? It's possible that your negative(s) are not up to the task. You need a negative that is too contrasty even for platinotypes, as salt prints have a very long scale. And remember, you really need to "overprint" salt prints. If it looks a little too dark, it's probably about right. The print will lighten up during your processing (wash, tone, fix...). Good note taking and a consistent light source are key as well.

cliveh · Mar 4, 2012

Gadfly_71 said:
This assumes, of course, that you're trying to simulate Fox Talbot's early work. Indeed, he did use NaCL early on but was unhappy with the results (he tried several methods to varying degrees of success). Herschel came up with Hypo (now known as Sodium Thiosulfate) as a means to permanently fix out the excess silver and passed the info on to Talbot (Herschel was very involved with many of the early chemical processes). Both Talbot and Daguerre switched to Hypo when it became clear that sodium chloride was not up to the task.

In answer to the OP. Sodium Thiosulfate is the fixer you want to use. As you've already noticed, Ammonium Thiosulfite is far too active for many of the older processes. Salt prints, Albumens, and VanDykes, all work best with plain Hypo. For VanDykes I use 1 heaping tablespoon of Hypo crystals to 1 quart of water. Works like a champ!

Cheers,
Andrew

Who else are we trying to simulate, he discovered the process. In terms of Salt Printing, which was originally discovered by Fox Talbot, I would suggest this is not the best advice. If you read notebooks P and Q you will see Sodium Thiosulfate was introduced for the Calotype. You are indeed correct in saying that sodium chloride was not up to the task. However, if you read between the lines of Talbots notebooks, you will see that even after the more practical process of complete fixing, he returns again and again to salt for its aesthetic value.

removed account4 · Mar 4, 2012

cliveh said:
No, you should use neither. If you follow Talbot's original notes you will see this was not used with his salt prints. As soon as you use fixer with a salt print you destroy the original colour. What you need to do is take a large saucepan of water and bring it to the boil. At the same time you keep pouring in as much salt (NaCl common salt) as will dissolve. What you are making is a super saturation salt solution. When no more dissolves, you let the solution cool. Bottle this and after exposure of your salt print pour this over the image. This will stabilise the salt print, but not fix it (having said this, I and Talbot have noticed that if you get the proportion of salt ratio in balance with the silver nitrate solution coated on the paper, it will be quite permanent, but this is a different story we wont go into here and one I can't do it consistently). You then need to scan it when dry before the image deteriorates.

hi cliveh

you can also use a super saturated salt solution to extract the silver from your rinse bath.
( hypo check is like a strong salt solution .. )
so it makes sense to me that this salt solution would remove unconverted/unused silver
from the print as well. i can't remember what percentage ( 10% just for an example ... ) the salt subbing is
pre-silvering wouldn't the saturated solution have to be 10% ( for example ) to be in equilibrium ?

i hope i am not being too technical, but is there a reason why a super saturated salt solution
can't be used as a regular fixer for a simple silver gelatin emulsion?

i would love to use something if i find myself in a bind ( and patrick gainer also suggested at one point a strong salt bath might work ) ...

john

Gadfly_71 · Mar 4, 2012

cliveh said:
Who else are we trying to simulate, he discovered the process. In terms of Salt Printing, which was originally discovered by Fox Talbot, I would suggest this is not the best advice. If you read notebooks P and Q you will see Sodium Thiosulfate was introduced for the Calotype. You are indeed correct in saying that sodium chloride was not up to the task. However, if you read between the lines of Talbots notebooks, you will see that even after the more practical process of complete fixing, he returns again and again to salt for its aesthetic value.

I respectfully disagree (I'm not really a fan of "reading between the lines"). The Talbot Museum at Lacock Abbey would disagree with this interpretation also.

My understanding (and of course my notes are packed in preparation for a move) was that he used the salt fixing more for his photogenic drawings and not so much for the prints from his calotype negatives. I'm also aware that much of the color difference in prints had lot to do with the sizing used in the different papers of the day (i.e., one color from arrowroot sized paper and another from gelatin sized paper). Also keep in mind, he improved his process many times before he was satisfied. His original photogenic drawings are very different from the salt prints he did later (the processes are related but not the same). The aesthetic value of a given print was always a bit secondary to permanence.

Post-Talbot workers almost always use(d) plain hypo for their salt prints.

Cheers,
Andrew

Mainecoonmaniac · Mar 5, 2012

Gadfly_71 said:
You need a negative that is too contrasty even for platinotypes, as salt prints have a very long scale. And remember, you really need to "overprint" salt prints. If it looks a little too dark, it's probably about right. The print will lighten up during your processing (wash, tone, fix...). Good note taking and a consistent light source are key as well.

You're probably right about the neg. It's a Polaroid type 55 neg cleared in sodium sulfite. It prints well on grade 3 paper, but too flat for salt prints. I first used my newly made UV light box and my print was disappointingly flat. But the 11A sun in Northern California sure added more contrast, but not quite enough. I might want to experiment boosting the contrast by using the potassium dichromate that came with the kit. I have started taking notes. It's sure a different world than silver gelatin printing. Love the look of salt prints though.

MDR · Mar 5, 2012

Great to hear that you like Saltprints an extremely underated process, that is unmatched in subtleties of tones imho. I'd use
Sodium thiosulfate rapid fixer bleaches to much. If you keep your prints mostly in the dark you can indeed use the salt method. Both salt and Hypo will change the color. When using rapid fixer it is even more important to tone the print before fixing either with Gold or Platinum toner

Dominik

Mainecoonmaniac · Mar 5, 2012

Hey Dominik. Thanks for the tips! Yes it is under rated. It's a gorgeous print. I think the popularity waned due to photogs in the days of old going for what's faster and convenient. It's what's happening now with ink jet printers.

Loris Medici · Mar 5, 2012

Maincoonmaniac,

Definitely try some FP4 souped in a Pyro developer (Pyrocat for instance...) - I mean instead of fiddling with dichromate. I'm not particularty familiar with salt-prints but dichromate doesn't actually boost constrast with iron-silver processes I use; it just decreases the speed considerably, giving an impression of high contrast, with the inherent price of lowering the dmax...

Definitely try gold toning too!

Fix in alkaline sodium thiosulfate fixer. (Dilute the formula 1+4...)

Good luck & regards,
Loris.

Mainecoonmaniac · Mar 5, 2012

Hi Loris,
Thanks for the tip. I have used PMK pyro and haven't used it in a while. The negative I was printing was from my files. If I shoot an image meant for salt prints, I'll use PMK pyro. It's a bit temperamental stuff. I've used FP4 with PMK Pyro and it seems to work well. However, I've heard on some APUG threads that I don't have to dunk the developed negs back into the developer for the stain. Still trying to figure that one out.

Best,
Don
aka Maine Coon Maniac

Jim Noel · Mar 5, 2012

Mainecoonmaniac said:
You're probably right about the neg. It's a Polaroid type 55 neg cleared in sodium sulfite. It prints well on grade 3 paper, but too flat for salt prints. I first used my newly made UV light box and my print was disappointingly flat. But the 11A sun in Northern California sure added more contrast, but not quite enough. I might want to experiment boosting the contrast by using the potassium dichromate that came with the kit. I have started taking notes. It's sure a different world than silver gelatin printing. Love the look of salt prints though.

I have been making successful salt prints for well over 15 years. If this negative prints well on Grade 3 paper, it definitely has far too low a density range to print well with salt. The closest you can get it to an appropriate range is to sepia tone the negative. It still will not quite be there, but it will be close. You would be better off to start over with an appropriate negative. FP4+ developed to totality is the best answer with modern materials. Too few people today have even heard of total development, and far less know how to achieve it. It is a simple process which needs to be learned. My first job in photography in the late 1930's was developing film, all of which was developed to totality. I still use the process today if iflm is to be printed with salt or albumen.

As for using concentrate NaCl as a fixer, Talbot never used this for prints from his calotypes. He did attempt it with photogenic drawings as well as his other early experiments. My conversations with Michael Gray, long time curator of Laycock Abbey, informed me that although unhappy with the difference in color, Talbot knew that he had to make concessions if his process was to endure. The use of rapid fixers will definitely change not only the density of the salt print, but also the color.

Jim

cliveh · Mar 5, 2012

Jim Noel said:
As for using concentrate NaCl as a fixer, Talbot never used this for prints from his calotypes. He did attempt it with photogenic drawings as well as his other early experiments. My conversations with Michael Gray, long time curator of Laycock Abbey, informed me that although unhappy with the difference in color, Talbot knew that he had to make concessions if his process was to endure. The use of rapid fixers will definitely change not only the density of the salt print, but also the color.

Jim

Jim, thanks for confirming my original statement, as I was trying to give the best advice.

Amonium Thiosulfite vs Sodium Thiosulfate for Salt printing

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