New at Salt Printing - Some problems

[philldresser]

I tried my hand at some Salt Prints this weekend with variable sucsess.

I used Food grade gelatin mixed with distilled water. Let it cool to around 40C.
To this I added my salt (approx 20g Sodium Chloride in 500ml ).

1. Spread sizing/salt solution evenly over a full sheet and allowed to dry overnight.

Next I added the silver nitrate and this is where the problems started.
First print :
2. Used 0.5 ml of AgNO3 and applied this in a line using a syringe.
3. I used a foam brush and spread the sensitizer over the area (5x4).
4. Allowed to dry 5 mins and force dried with cool hair dryer for 5 mins.
5. Exposed using UV lamps (Solarium) for 6 mins

Result was a very weak image - very pink in colour, limited tonality except over the area where I deposited the Silver solution. This was dark brown/black.

Print 2
1. Same as 1
2. Coated the print area over the sizing and allowed to dry.
3. Applied the 12% silver solution (0.5ml) over print area using glass rod instead of foam brush and allowed to dry
4. Exposed for 6 mins

Result was same as print one.

Left it overnight to stop frustration setting in. Surfed the net, consulted my books etc and read everything again and came up with a potential answer. Seems the salt/silver ratio was out.

Print 3 (see attachment)
1. Dumped the gelatin and made fresh batch without the salt. Coated a sheet and started again.
2. Mixed a 3% NaCl solution in distilled water.
3. Applied the sizing solution
4. Applied a thicker coating of silver nitrate (1ml) using foam brush and exposed.

This time I at least got a complete image across the whole area but had a deep pink tone. After washing, fixing and drying I can see that I am under exposed so will need to try again with more exposure.


So to my questions to all you (S)Alt Printers:
1. Should I be able to get decent results with these ingredients? Recipes stipulate ammonium chloride but mine hasn't arrived yet so I tried Sodium Chloride. Also Potassium citrate, this also hasn't arrived yet so missed it out.
I beleive this is just for colour!

2. Should I carry on trying or wait for the real chems?

3. What quantity of the silver solution should I use for a 5x4 image. I assumed (wrongly) that it would be about the same as a cyanotype (0.4ml per 4x5)

Cheers


Phill


I have attached my first full print for reference. Note the lack of contrast, no max density and the overall pink tone.

 

[philldresser]

Addendum

Also noted that Selenium Toning salt prints did not work very well for me. I found no references to Se toning anywhere so gave it a try but got very mucky results. Solution was 1:29 (KRST). Anyone else tried this on Salt Prints?

Phill

 

[Donald Qualls]

I've gotten good density with salt prints made with either straight sodium chloride or a mix of sodium chloride and potassium bromide (the latter seems a little faster, but has higher contrast and narrower range). I'd first note that a negative that prints well in silver gelatin probably lacks contrast for salt printing; this and other silver-based printing out processes are "self masking" in that the silver image that appears during exposure blocks further exposure in the same area, which tends to compress contrast (especially in the darker tones). It looks to me, from my attempts so far, that I need to both expose *and* develop my negatives longer for salt prints (more exposure to get the shadows off the toe so they have better separation, and more development to boost overall contrast).

My prints are always very warm toned when simply exposed, washed (to remove residual silver nitrate or convert it to chloride), fixed, and washed (to remove fixer residue), though not quite as much so as VDB. From examples I've seen, use of ammonium chloride in place of sodium chloride may change the image tone, and of course toning with selenium (very, very dilute; the solution contains rapid fixer and will bleach the print) or gold changes the print tone quite a bit as well.

I'd be tempted to try a bleach/redevelop sepia tone on a salt or VDB print, if I had the chemistry for it...

 

[nworth]

Was it the salt? Table salt often includes additives, including ferricyanide which can kill the speed of anything photographic even in very small quantities. If you are unsure of the salt, you might try again using either ammonium chloride or reagent (well, practical grade would do, but for chemical use) sodium chloride.

 

[roy]

While not having any knowledge to contribute, I shall watch this thread with interest as I am about to try making salt prints. I have seen reproductions of prints, which I have been led to understand were made by the process, that were a "steely blue" in colour and I was wondering if this colouration could be achieved with a gold toner as with some silver gelatine papers.

 

[Ole]

Sodium chloride should work just fine, as long as there aren't too much additives in it.
I use sea salt, which is pure enough (not "flor di sel", but coarse crystals).

You need negatives with a really, really long scale for good results. Staining developers help a lot in this.

Gold toner is a very good idea to shift the colour from brown to blue-black. Platinum or palladium toner works great too.

 

[Lukas Werth]

You lack citric acid (or an equivalent)! Read James Reilly (see my comment to another post about albumen and salt prints), this will give you, as far as I can see, the best systematic overview of the technique available. An organic ingredient is necessary to "activate" the silver nitrate.

 

[Lukas Werth]

An additional thought, after looking at your scanned image: does your negative have the right contrast? It needs to be very high, considerably higher than, for instance, normal pl/pd!

 

[juan]

And what is the ph of your wash water - the initial wash? It needs to be into the acid range, too. I have to add a bit of citric acid to my water, too.

Paper will also affect print color, scale, etc. You might want to experiment with several papers.

I'm finding salt printing to have a great number of variables to work through.
juan

 

[smieglitz]

Try a small batch of this:

- Non-iodized table salt at about a 1.5% concentration.
- Increase the silver nitrate to a 20% concentration and bring the pH to about pH2 using acetic acid.
- If your negative is not dense/contrasty enough try selenium toning it (1+3) for about 5 minutes.

Joe

 

[philldresser]

Thanks to all for responses.

Lukas - I am not sure of the density range of the neg but it is substantially more contrasty than my normal offerings. I made the neg as a test on Cyanotypes (there was a url link here which no longer exists)

Ole, nworth - I used table salt which has some anti-caking agents in it.
Juan - I used a weak citric acid first wash. My water here is slightly alkaline and hard.


Some things I can try differently next time:
Use ammonium chloride,
Use photographic gelatin,
Add a citrate to boost colour and contrast.
I will try and order a Stouffer step again (They ignore my emails) to monitor my density range.

I can selenium tone a neg because I do have a copy. I would then be able to do a side by side comparison.

At some point when I mix my own silver I will try the smieglitz suggestion.

I am still unsure of the volume of sensitizer required (Silver Nitrate) to cover a 5x4. Is it more than the cyanotype sensitizer? Anyone have a rule of thumb that works for them?

Cheers

Phill

 

[juan]

Thanks to all for responses.


I am still unsure of the volume of sensitizer required (Silver Nitrate) to cover a 5x4. Is it more than the cyanotype sensitizer? Anyone have a rule of thumb that works for them?

I've lately been using two coats of 1ml each for 8x10.
juan

 

[Photo Engineer]

I have never heard of table salt containing any ferricyanide.

Caking agents should not hurt you, but iodide, often found in table salt, will change the characteristics of the final material.

PE

 

[Jim Noel]

I think I had every problem possible until I switched to Kosher Salt. This coupled with negatives having a density range of about 2.1 produces very nice prints.

 

[Gerald Koch]

I have never heard of table salt containing any ferricyanide.

It doesn't. But Morton kosher salt does contains sodium ferrocyanide (sometimes potassium ferrocyanide, yellow prussiate of potash) not sodium ferricyanide.

To the poster who mentioned ferricyanide, be careful, ferricyanide and ferrocyanide are two diffent things.

For photographic purposes it is better to use pickling salt.

 

[Photo Engineer]

It doesn't. But Morton kosher salt does contains sodium ferrocyanide (yellow prussiate of potash) not sodium ferricyanide.

To the poster who mentioned ferricyanide, be careful, ferricyanide and ferrocyanide are two diffent things.

For photographic purposes it is better to use pickling salt.

Gerald, I wouldn't even want salt with ferrocyanide.

Every mole will still liberate 6 moles of cyanide with enough acid such as the HCl in the stomach. At low levels this may not be toxic and may not even release the cyanide, but if it does it could cause breathlessness or dizziness in the person who consumes it.

How odd. You learn something new every day. Now I have to check it out next time I'm at the supermarket.

PE

 

[Lukas Werth]

It is not ecessary to switch to ammonium chloride, nor to use chemically pure salt - I did it first, and compared results with table salt which works fine, even with iodine, but this changes tonality, so I would use just the plainest, cheapest salt available in your local super market.
The quality of the gelatine also should not matter too much (it's more important with gum prints and the like), though gelatine of dependable quality is available from Kremer pigments, and considerably cheaper than what you get in an alimentary store, at least here in Germany.
First wash Water ph also does not matter at all with this process. The water just has to run milky.
You will certainly improve results with citric acid added to the silver nitrate and/or to the salting (both is probably best), be aware that this reduces the permanence of the silver nitrate solution to a few months.
About contrast: not being a subscriber, I cannot see your picture, but cyanotype is a funny process, more flexible than most people think. However, negatives for salt prints should be MUCH MORE CONTRASTY than what is normally thought adequate for c., more than for any other process exept pure palladium printouts. Density range should be about 3.0, that is, such a neg is useless for normal promide enlarging.
I suggest you get yourself a 21 step Stouffer scale (google Stouffer) - very inexpensive, costs you less than a kg of ammonium chloride - and expose it alongside the negs you print. This gives you a very good idea of density ranges required for different processes and negs.

 

[Ole]

I can selenium tone a neg because I do have a copy. I would then be able to do a side by side comparison.

Instead of selenium toning, let me suggest bleaching and redeveloping in a staining developer.

I've got good results from a "normal" negative that was bleached, then redeveloped in a "pyro/soda developer": 1/2 liter of water, 1 tsp pyro, 1 tsp soda (NaOH). No sulfite at all, so the developer dies within minutes. Mix each constituent in half the final volume, then mix the two immediately before putting the negative in.

 

[Gerald Koch]

The amount of ferrocyanide in Morton kosher salt is quite low and not dangerous. BTW, a dilute solution of hydrocyanic acid was once used as a treatment for excess stomach acid and heartburn. No it wasn't a permanent cure. ;-) As far a poisons go there are many things far more poisonous than cyanide.

As I said, pickling salt is probably the best choice when sodium chloride is needed for photographic purposes. There are no insoluble anticaking chemicals in it like silica. Works very well for homebrew Microdol-X or Perceptol and should be fine for alternative processes.

 

[philldresser]

Lucas

Attached is the cyanotype for reference. Density is definitely not 3.0.

Ole. Do you think it would be worth trying to redve in Pyrocat-HD. Is this staining enough?

Phill

 

[Donald Qualls]

The salt I've used was sold as "kosher salt" -- it's listed as containing a tiny quantity of "yellow prussiate of potash" aka potassium ferrOcyanide -- which is not the same as ferrIcyanide used in photographic bleaches. I'm still working on getting enough contrast, however, and I think much of that has to be done on the negative side.

 

[Ole]

Ole. Do you think it would be worth trying to redev in Pyrocat-HD. Is this staining enough?

I think it should be, although I haven't tried that myself. When I did that, I had no pre-made Pyrocat-HD left. So I just took the basic raw mateials to make an ultra-staining "developer". The negative was cr*p as it was (and a backup besides), but the increased contrast made it just right for POP and salt prints.

 

[philldresser]

The negative was cr*p as it was (and a backup besides), but the increased contrast made it just right for POP and salt prints.

Is this a guarentee that I can get winners from all my cr*p negatives?

I mixed up a batch last night so will give the pyrocat a try and see what happens.

Phill