Salt-Free Salt Print Toned with Himalayan Black Salt

[nmp]

So I tried to bleach tone a salt print test strip prepared as per the procedure outlined in the head post.

From left to right:
A = Control, untoned
C= Toned direct with 0.5% Kala Namak for 10 mins
B= Bleached/rehalogented + 0.5% KN then added more to make 2% anf then added Na2CO3 to adjust the pH to about 10.



C is as I expected - tone changes to more neutral almost eggplant-like with improvement in Dmax, same as what I have seen before.

B at first gave only a faint tone with 0.5% KN so added more to make up 2%, which increased the toning somewhat, but barely. So added some 1% Na2CO3 to increase the pH. Did do a better job, but even after several hours, the result was only a faded version of the original as seen in A.

So the results are quite opposite to Raghu's findings above on positive film. I guess perhaps there is a reason why there is almost no literature for indirect sulfide toning of salt prints, that I know of that is.

 

[Raghu Kuvempunagar]

So the results are quite opposite to Raghu's findings above on positive film. I guess perhaps there is a reason why there is almost no literature for indirect sulfide toning of salt prints, that I know of that is.

What is the image in a salt print made up of? Is it silver or some compound of silver?

 

[nmp]

What is the image in a salt print made up of? Is it silver or some compound of silver?

It's metallic silver - just like a silver gelatin print. Particles are much smaller, hence the reddish color. Also they are sitting in the paper fibers as opposed to dispersed in a gelatin matrix - particularly when there is no external sizing such as gelatin or starch etc used - as is the case in my salt prints.

:Niranjan.

 

[Raghu Kuvempunagar]

It's metallic silver - just like a silver gelatin print. Particles are much smaller, hence the reddish color. Also they are sitting in the paper fibers as opposed to dispersed in a gelatin matrix - particularly when there is no external sizing such as gelatin or starch etc used - as is the case in my salt prints.

Could it be that the rehalogenating bleach acts like a blix on such very small silver particles and therefore removes most of them leaving behind only the bigger particles that are difficult to tone directly? Have you tried bleaching with a substantially more diluted bleach and for shorter duration of time? Just hazarding a layman guess on what might be taking place.

P.s. is your rehalogenating bleach Chloride based by any chance?

 

[nmp]

Could it be that the rehalogenating bleach acts like a blix on such very small silver particles and therefore removes most of them leaving behind only the bigger particles that are difficult to tone directly? Have you tried bleaching with a substantially more diluted bleach and for shorter duration of time? Just hazarding a layman guess on what might be taking place.

P.s. is your rehalogenating bleach Chloride based by any chance?

It almost certainly has something to do with the particle size - that would be my guess too. But how - Is the re-halogenating bleach* also eating away some of the silver? That's a good question. One other data point I have is that I have been able to regenerate the silver by redeveloping with a vitamin C developer, as I discussed in this thread (see step B to step C):

https://www.photrio.com/forum/threads/additive-prussian-blue-toning-of-silver-based-prints.177686/

There, in addition to silver, there was also ferric hydroxide present so it was not quantitative as to how much density got redeveloped back compared to what was there before. I guess I might have to do an experiment with only the salt print + bleach/re-halogenate + redevelop sequence.

:Niranjan.


*My bleach is 0.2% K Ferricyanide + 0.2% KBR, substantially more dilute than the one you shared above. It does take some time to fully bleach - about 1/2 hour.

-

 

[Raghu Kuvempunagar]

One other data point I have is that I have been able to regenerate the silver by redeveloping with a vitamin C developer, as I discussed in this thread (see step B to step C):

https://www.photrio.com/forum/threads/additive-prussian-blue-toning-of-silver-based-prints.177686/

There, in addition to silver, there was also ferric hydroxide present so it was not quantitative as to how much density got redeveloped back compared to what was there before. I guess I might have to do an experiment with only the salt print + bleach/re-halogenate + redevelop sequence.

I have seen your thread on additive toning before and I must say it left me highly impressed. Very nice work! I have something to add to the subject but that's for the distant future. Today I got hold of Keya brand pink salt as I was curious to find out how it fares as a toner. As before I attempted indirect toning of a scrap slide with the salt solution. Unfortunately, there was not any noticeable toning. I checked pH of the salt solution and it was between 6 and 7. So I added a little Sodium carbonate and tried toning again. Yet nothing much happened and I discarded the pink salt solution. Next I repeated the earlier experiment of using Keya brand black salt for indirect toning. pH of the salt solution was around 11 and I got nicely sepia toned slides in about a minute. So I guess pink salt isn't quite the same as black salt when it comes to toning, at least as far as Keya brand salts are concerned. Fortunately, pink salt tastes a lot better than the black one and I can put it to good use in the kitchen.

 

[nmp]

I have seen your thread on additive toning before and I must say it left me highly impressed. Very nice work! I have something to add to the subject but that's for the distant future. Today I got hold of Keya brand pink salt as I was curious to find out how it fares as a toner. As before I attempted indirect toning of a scrap slide with the salt solution. Unfortunately, there was not any noticeable toning. I checked pH of the salt solution and it was between 6 and 7. So I added a little Sodium carbonate and tried toning again. Yet nothing much happened and I discarded the pink salt solution. Next I repeated the earlier experiment of using Keya brand black salt for indirect toning. pH of the salt solution was around 11 and I got nicely sepia toned slides in about a minute. So I guess pink salt isn't quite the same as black salt when it comes to toning, at least as far as Keya brand salts are concerned. Fortunately, pink salt tastes a lot better than the black one and I can put it to good use in the kitchen.

Thanks, Raghu.

Did some googling - it is confusing with all these terms. Some more background on various versions here:

https://www.thebetterindia.com/2578...k-benefits-nutritional-experts-advice-ros174/

So it looks like the Himalayan pink salt, is mined from the salt caves in Himalayas and sold as is in either coarse or finely ground forms. In India, it is commonly known as Sendha used primarily in cuisine in lieu of table salt during religious festivals. I am guessing it does not smell sulfurous - it is mostly made of sodium chloride and some other minerals. I am not surprised that it did not produce any toning for you.

Kala Namak or black salt is a processed derivative of the above pink salt with many external additives including sulfides (hence the smell) which is also sold in coarse or powdered form. The latter takes on lighter color, pinkish to grayish, so it can be confused with the ground pink salt. One I used is the powdered Kala Namak (I like this term better than Black Salt because it clearly signifies Himalayan origin than other black salts that come from many other parts of the world.) Your first Keya product seems to be the coarse Kala Namak. I am now curious as to why the coarse form is so alkaline, so I am getting this:

https://www.amazon.com/dp/B07D96SVD2?psc=1&ref=ppx_yo2_dt_b_product_details

It looks very similar to your first Keya black salt. I will compare it against my powdered form.

:Niranjan.

 

[Raghu Kuvempunagar]

So it looks like the Himalayan pink salt, is mined from the salt caves in Himalayas and sold as is in either coarse or finely ground forms. In India, it is commonly known as Sendha used primarily in cuisine in lieu of table salt during religious festivals. I am guessing it does not smell sulfurous - it is mostly made of sodium chloride and some other minerals. I am not surprised that it did not produce any toning for you.

Thanks for the insight on the pink salt. The only reason I tested this salt was because the scientific analysis that I shared earlier in post #28 reported high amount of Sulphur in it. However, it's very much possible that the particular brand I used doesn't have sufficient amount of Sulfides to tone B&W film. As Kala Namak serves the purpose of toning, I'll continue to use it and not experiment with other brands of pink salt.

 

[nmp]

Thanks for the insight on the pink salt. The only reason I tested this salt was because the scientific analysis that I shared earlier in post #28 reported high amount of Sulphur in it. However, it's very much possible that the particular brand I used doesn't have sufficient amount of Sulfides to tone B&W film. As Kala Namak serves the purpose of toning, I'll continue to use it and not experiment with other brands of pink salt.

Yeah, it looks like that the paper used "pink salt" as a generic term that included salts from the so-called Pink Lake in Australia as well (which seem to be having the most amount of sulfur, by the way.) Most of the Himalayan based salts seem to be Kala Namak variety - either ground or granular, but can't say for sure without checking each brand for contents.

Here is the latest on salt print experiments: I took a strip, bleached/re-halogenated with the same bleach formulation I used before (post #36,) sunned it for a while and then redeveloped for 15 minutes using ascorbic acid developer (basically 1% AA in 1% Na2CO3.) The result:



A = Control, untoned
D = Bleached/re-halogented + exposed + redeveloped

As can be seen, almost all of the density is back - there is slight diminishing but nothing compared to the loss of density in the case of indirectly toned sample (B in post #39.) More pronounced is the shift to more yellowish tone that might signify smaller grains as a result of the round trip. So it would seem not too much of the silver is lost during bleaching.

:Niranjan.

 

[Raghu Kuvempunagar]

As can be seen, almost all of the density is back - there is slight diminishing but nothing compared to the loss of density in the case of indirectly toned sample (B in post #39.) More pronounced is the shift to more yellowish tone that might signify smaller grains as a result of the round trip. So it would seem not too much of the silver is lost during bleaching.

Interesting! So what is going wrong with indirect toning?

 

[nmp]

Interesting! So what is going wrong with indirect toning?

No idea. May be just not that active. I will use this other granular Kala Namak that looks like yours and see that makes a difference.

 

[Raghu Kuvempunagar]

I created a resource page for anyone who wants to try Kala Namak indirect toning on slides and silver gelatin prints.cc: @Ivo Stunga you might find the resource useful.

 

[nmp]

I created a resource page for anyone who wants to try Kala Namak indirect toning on slides and silver gelatin prints.cc: @Ivo Stunga you might find the resource useful.

Thanks. That's excellent.

So I got the granular/coarse form of Kala Namak yesterday and I tried it out:

1) It seems more sulfurous based on the smell and the color, perhaps a tad bit faster, but by and large comparable from the direct toning perspective to the older powdery stuff I have.

2) pH is no different, still neutral so it seems the Keya one might be unique in that regard.

3) Indirect toning no different from before - so no improvement.

On the other hand, now I have a lifetime supply of the stuff.

:Niranjan.

 

[Raghu Kuvempunagar]

So I got the granular/coarse form of Kala Namak yesterday and I tried it out:

1) It seems more sulfurous based on the smell and the color, perhaps a tad bit faster, but by and large comparable from the direct toning perspective to the older powdery stuff I have.

2) pH is no different, still neutral so it seems the Keya one might be unique in that regard.

3) Indirect toning no different from before - so no improvement.

Thank you doing these tests. It's quite intriguing that for salt prints, direct toning using Kala Namak works fine but not indirect toning whereas for B&W film slides the exact opposite is true. Someday we will find an explanation I'm hopeful.

 

[MattKing]

If anyone would like to have anything moved from this thread to a new thread, please start the new thread and then give me instructions which posts you would like moved, and I'll have a go.
Even if we don't move any posts, it seems to me that a new thread on the subject of toned transparencies makes a lot of sense, even if it just refers to this thread, and then goes on from there.

 

[nmp]

Here are couple of scans from the slides above:

EDIT: removed scans that showed the wrong color cast - massively different from what's projected.

Sorry for that, will do better.

You didn't need to remove them - just a note would have been OK. We could have still admired the other aspects of it.

:Niranjan.

 

[Raghu Kuvempunagar]

If anyone would like to have anything moved from this thread to a new thread, please start the new thread and then give me instructions which posts you would like moved, and I'll have a go.
Even if we don't move any posts, it seems to me that a new thread on the subject of toned transparencies makes a lot of sense, even if it just refers to this thread, and then goes on from there.

@MattKing: If you give me some time I can create a thread that discusses various toners for B&W slides including Thiourea, FSA, Catechol and Kala Namak as the subject of toning slides is more general than Kala Namak. Or if you feel Kala Namak toning of slides is itself a good subject for a thread, here is a thread I created just now and you can move post #10, 11, 12, 18, 19, 29, 30, 31, 32, 35, 39, 47, 49, 51, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 69, 70, 71, 72, 73 to that thread. If I missed any post that should be in the Kala Namak toner for slides thread, please add to the list.

 

[MattKing]

I've started the moving of posts with all posts from 69 and later - it will take a bit, and some things may look weird for a bit.

 

[MattKing]

The movement of posts is now complete. I'll copy Raghu's introductory post to the beginning post of the new thread, and put cross-linked warnings at the beginning of each thread referencing the thread "surgery".

 

[MattKing]

Phew - it is now done. Hope this helps.

 

[Raghu Kuvempunagar]

Phew - it is now done. Hope this helps.

It surely does. Thanks @MattKing.