Here's what has me all worked up: I successfully printed photograms with non-chloride silver salts. I tested out potassium iodide and Old Workhorse Bromo-Iodizer as catalysts for salt printing, along with a sodium chloride control print and an ammonium chloride side-test. Everything produced a clear, visible image. I'm going to discuss first the basic parameters of the experiment, the controls, and then get into the preparation and results for each halide solution.
|Test sheets prior to exposure.|
All but one show significant fogging.
Bromo-Iodizer Solution: I used the Bostick & Sullivan Old Workhorse Bromo-Iodizer directly out of the bottle, with no changes to the solution. The solution is easy to coat, and has a strong yellow color that makes it easy to tell where your paper has been coated. It smells strongly of alcohol and should be used only in well-ventilated areas. The bottle should be capped immediately after the solution is extracted.
Potassium Iodide Solution: This chemical comes as a transparent/white crystal solid. I mixed 6 grams of the crystals into 200ml of water to make a 3% solution. I didn't use nearly so much, but I didn't have a small enough mixing container to measure less than 200ml water with accuracy.
Ammonium Chloride Solution: This is a shiny white powder that does not readily dissolve in water. It required a lot of stirring, and left a film of bubbles and fragments floating in the solution. Again, I mixed the same 6 grams of solid to 200ml of water, resulting in a 3% solution.
The prints were made in windows at my apartment, on a clear, sunny day. I exposed all four prints for 2 hours before pulling them and scanning the resulting images. None of them have been fixed, though I may do a potassium iodide fixing test just to see what happens.
So, my final thoughts? I'm very excited to have proven to myself that silver chloride is not the only halide that can be used in salt printing. The potassium iodide image is considerably blander than I had hoped for, but the strange jade color of the bromo-iodizer image gives me hope for future tests. I still haven't tested potassium bromide by itself, or tested non-potassium forms of bromide and iodide. I know from previous experience that potassium chloride isn't the best form of chloride to use, so maybe potassium bromide and potassium iodide aren't the best forms of those halides, either. I'm going to look into obtaining other solutions of bromide and iodide, maybe even some alternate forms of chloride. The ammonium chloride is similar enough to sodium chloride, but I've yet to test pure potassium chloride to see the result. I've only ever used it in a "lite salt" mixture: 50% sodium chloride and 50% potassium chloride.
There's just so much more to do, Spiders!