How long do gold toned salt prints last?

[utsavgupta]

Over the past few months I have been experimenting with the salted paper printing process.

The goal was to have some of my photographs salt printed, framed, and on display in my living room.

I was under the impression that gold toning ( either the borax or sodium bicarbonate recipes) the prints will make them last as long as platinum prints, or atleast ones lifetime.

But the more I read about them online I feel salt prints, even if they are toned, may not be ideal to be hung in one's living room. They are rather delicate and would fade or deteriorate eventually unless they are stored in a dry and dark place.

I would love to hear from the salt printing veterans about the permanence of these prints. And whether it makes sense to have them framed.

Thanks,

Utsav

 

[fgorga]

Since no one else has responded, I'll give it a go even though I am not an expert.

From a chemical viewpoint, a gold toned salt print will certainly be more stable than an untoned print but probably not quite as stable as a platinum/palladium print.

That said, my feeling is that you are under estimating the stability of a properly processed salt print... by properly processed, I mean completely fixed and then well washed.

I would not hesitate to display a salt print on my wall as I would any other photograph. However, I would not display any photo where it would be exposed to strong, direct sunlight for a significant interval.

 

[koraks]

by properly processed, I mean completely fixed and then well washed.

This is the crucial issue. The gold isn't so much an issue; in chemical terms, it should be stable enough to last a century on display in a typical living room. Assuming that the toning is taken to completion; i.e. most of the silver has been replaced by gold.

The problem with gold-toned salt prints, and also untoned salt prints, is the difficulty of removing all traces of unreacted silver halide from the paper as well as the silver complexes that emerge during fixes. Due to the nature of the paper we use, which is a very open structure to which particles adhere readily (as opposed to baryta or even PE paper used for regular darkroom printing), it's very, very difficult to wash a salt print well. Sometimes it even proves to be practically impossible!

The result is that yellowing/browning of the highlights and white borders of the print. This process is accelerated by UV light and by heat, so it can be slowed down by storing the prints in the dark, but it cannot be stopped by practical means nor can it be reverted.

In my experience, it's particularly difficult to cleanly wash salt prints that are gold-toned before fixing; interestingly, prints toned with gold after fixing wash much more easily. The downside is that gold toning IMO works especially well (fast, to completion, with beautiful blue/blacks) when done before fixing.

To verify the quality of your processing, I recommend the following:
1: Always print with a masked border that ensures you have an area on the paper that is sensitized, but completely unexposed. This will help you see if your whites clear properly - and remain clear in due course! Furthermore, it helps to have a masked area adjacent to an unsensitized area of the paper so you can see the difference between the pure paper and the paper that has had silver sensitizer applied to it.
2: Make a test print and 'torture' it - feel free to dry it by applying a clothes iron to it at its highest heat setting (there's no gelatin layer to be worried about anyway!), put it next to a south-facing window, etc. Verify if the masked borders remain clear. There's about a 99% guarantee that you will see at least some discoloration in this border compared to the pure (unsensitized) paper. The degree how badly it discolors is an indicator of the quality of your processing.

I feel salt prints, even if they are toned, may not be ideal to be hung in one's living room.

Be that as it may, given the story above, consider that if you enjoy making them, and if you like the end result, there's no reason to abstain from adorning your living quarters with these prints! If in 10 years' time they have discolored so badly that you no longer like the prints...make some new ones

 

[Tom Taylor]

"But the more I read about them online I feel salt prints, even if they are toned, may not be ideal to be hung in one's living room. They are rather delicate and would fade or deteriorate eventually unless they are stored in a dry and dark place."

I have untoned salt prints hanging on the wall since 2013 and they look as good today as the day when they were printed. One was mounted using OP3 museum grade acrylite https://www.tapplastics.com/image/pdf/a_OP3_tech_data.pdf in 2015 and, depending on how my patio blinds are closed, can receive about 2 hours of weak daily sunlight reflected off an office window some distance away. The other was mounted in 2013 using plain glass but is not exposed to direct or reflected sunlight. As I said, there has been no noticeable change in either over the years.

Thomas