Developed-out Salted Paper Prints

[Ethan Brossard]

Sorry to resurrect this thread yet again, but I'm hoping to attempt some DOP salted paper prints, and I have a few questions on the processes you guys have used. I'm mainly curious as to the formulas you use for each step, Below I've written down what I've researched as to what the process should be, but If you notice any mistakes I would be grateful if you could point them out.

First step, salt the paper:
For normal salt prints 25 grams per liter is what I've read, should that work fine here as well?
Brazile also mentions adding a bit of citric acid and baking soda (sodium bicarbonate) to the salt, how much of those do you add?

Sensitize the paper:
Sensitize with 5% silver nitrate solution, with added citric acid again. How much citric acid is added here?

Expose:
expose until image is faintly visible

Develop:
saturated bath of gallic acid with some citric acid. My research says 1 gram of gallic acid is soluble in 87ml of water, so 11.4 grams in 1 liter, does that sound about right? Again, how much citric acid should be added?

Fix and wash as one would a normal salt print, with a sodium thiosulfate fixer and then optional sodium sulfite to reduce wash times.

Am I missing anything? I guess the main thing I'm wondering is how much citric acid to use in the steps which require it.

Thanks!

 

[NedL]

Am I missing anything? I guess the main thing I'm wondering is how much citric acid to use in the steps which require it.

These are guesses, based on printed-out salt, but maybe some of it will help:

When I've added CA to the salt solution, it's always been just a little ( < 0.5% ) and just as a little extra help in reducing fog and keeping the highlights clean. It depends a lot on what kind of paper you use whether this is helpful or needed. If you add citric acid + sodium carbonate ( which is "washing soda", not "baking soda" ), that adds some sodium citrate. Adding sodium citrate to the salting solution changes the color, speed, and contrast of the print in POP salt.

Adding CA to the sensitizing solution acts as a bit of a restrainer and helps reduce fogging and keep the highlights clean. Again the effect depends on what kind of paper you are using. Usually with no CA at all, you will get some fog... and above 6% or so you will start to restrain the printing too much and get harsher contrast ( losing highlight details ). I don't know if this will play out the same way in DOP. When I make POP salt, I add different amounts of CA depending on what paper I am using....

In development, CA acts like a restrainer, slowing things down and keeping the highlights clear, while adding silver nitrate speeds things up. When I'm developing calotypes, I keep the CA and acidified-AgNO3 in eyedropper bottles and add drops as needed depending on how the development is going. So, tiny amounts! Gallic acid is a little difficult to dissolve in water, and at least for calotypes, a solution of 1.4 g/100ml works just as well as saturated and is easier to make. During development, the gallic acid can decompose ( it will make black sludge, which will appear on the sides of the tray and on the print... if it gets on the print you can wipe it off gently )... so it's probably best to make only as much as you will use to develop your print. 100ml is convenient, and enough to develop even a large print.

Would be very interested to see or hear about your results.
Good luck and have fun!

 

[Ethan Brossard]

Thanks for your help!

 

[Ethan Brossard]

To those of you who have managed the gallic acid developer version of salt, how do you add the silver nitrate to the developer when needed? I'm attempting this process, but have been getting insufficient density, and when I add silver nitrate to the developer, it seems to add density across all the print, darkening highlights as well as shadows the same amount.

 

[brazile]

To those of you who have managed the gallic acid developer version of salt, how do you add the silver nitrate to the developer when needed? I'm attempting this process, but have been getting insufficient density, and when I add silver nitrate to the developer, it seems to add density across all the print, darkening highlights as well as shadows the same amount.

Sorry, I haven't checked in here in quite a while. The way I learned it was to use a (preferably glass, e.g., Pyrex) developing tray propped up on something so it's at an angle. The developer is poured into the bottom of the tray, and brushed gently onto the upper part of the tray. The print is then placed on the upper part of the tray, and tends to stay there because of the wet glass; you then brush the developer from the pool at the bottom onto the print using something like a wad of cotton wool. Keep doing this, concentrating your brushing onto the areas that seem to need more density until you either get the density you're looking for, or you decide you need to punch it up a bit with a few drops of silver nitrate.

The silver nitrate is added to the pool of developer (i.e., not directly on the print!) in a quantity on the order of a drop or two. Then you brush gently only the parts of the print you need to build the density in. Brush more developer on, building density as you go. You can repeat the addition of a couple drops of silver nitrate if you like, but go easy with it in order to avoid the kind of fogginess you describe.

I do not claim to be an expert at this technique by any stretch, but it does seem to work for me. At least, it works well enough that I'm persuaded that with practice my results would continue to improve.

It is probably time for me to get back to this; I was off chasing other pursuits since last spring (2021) and I'm only now getting back to making dry plates and printing from them again...

As for the previous question about citric acid: Ned pretty much has it, as I recall it. I'll look in my notes to see what amounts I used, but I think it was about as he said.

Robert

 

[Ethan Brossard]

Sorry, I haven't checked in here in quite a while. The way I learned it was to use a (preferably glass, e.g., Pyrex) developing tray propped up on something so it's at an angle. The developer is poured into the bottom of the tray, and brushed gently onto the upper part of the tray. The print is then placed on the upper part of the tray, and tends to stay there because of the wet glass; you then brush the developer from the pool at the bottom onto the print using something like a wad of cotton wool. Keep doing this, concentrating your brushing onto the areas that seem to need more density until you either get the density you're looking for, or you decide you need to punch it up a bit with a few drops of silver nitrate.

The silver nitrate is added to the pool of developer (i.e., not directly on the print!) in a quantity on the order of a drop or two. Then you brush gently only the parts of the print you need to build the density in. Brush more developer on, building density as you go. You can repeat the addition of a couple drops of silver nitrate if you like, but go easy with it in order to avoid the kind of fogginess you describe.

I do not claim to be an expert at this technique by any stretch, but it does seem to work for me. At least, it works well enough that I'm persuaded that with practice my results would continue to improve.

It is probably time for me to get back to this; I was off chasing other pursuits since last spring (2021) and I'm only now getting back to making dry plates and printing from them again...

As for the previous question about citric acid: Ned pretty much has it, as I recall it. I'll look in my notes to see what amounts I used, but I think it was about as he said.

Robert

Thank you so much! I was trying to develop normally in baths, and that wasn't working at all! I'll try this method when I have a chance.

 

[Ethan Brossard]

I've had a thought.

I gather that the reason traditional chemical developers don't work for salt prints is that the excess silver nitrate on the paper gets developed as well as the exposed silver halides, thus turning the image pitch black soon after development is finished. Is that true? Might it be possible to coat the paper in a way that avoids the presence of excess silver nitrate? I'm imagining doing something more like kallitypes, such as combining silver nitrate with a sodium chloride solution without a salt bath, and then coating it on the paper. If a stronger then necessary salt solution is used, I presume all (or at least most) of the silver would bond to form halides, and thus there wouldn't be an excess to fog the image during development.

Might that work? I've done my fair share of experiments in the darkroom, but don't have any chemistry background.

 

[koraks]

Is that true?

Probably, yes.

Might it be possible to coat the paper in a way that avoids the presence of excess silver nitrate?

Probably, but if you work out the methods to do so, you would probably just be re-discovering silver gelatin papers or a rendition thereof.

Might that work?

Don't think so because you'd still be stuck with a lot of silver halide embedded in a poorly controlled substrate.

 

[nmp]

I have some new work on this topic here that might be of interest.

:Niranjan.