NedL
Subscriber
I just had a bit of a revelation. There are posts here at APUG saying not to coat your salt prints under a safelight, because you need to be able to see what you are doing. Those people know what they are talking about and I should have heeded their advice!
I made a calotype + salt print for MSA, and the calotype has some bad stains on it. But I was a little disappointed that the most glaring problems in the final print have to do with the salt print and not the calotype. I just looked back through a stack of salt prints, about 40 of them, and it is obvious that my problems with coating have gotten worse over time. The last 4 are by far the worst, with streaks and sections left uncoated or weakly coated. My first dozen were very evenly coated with almost no streaks at all except around the edges.
So, just now, I decided to try another, and I closed the blinds in my study, turned on an incandescent light, and sat at my desk where I could see. Well, it was obvious what's been happening. The AgNO3 solution is simply not going onto the paper as smoothly as it used to. The brush is leaving streaks of uncoated paper. Under the safelight, these were too hard to see. Even though I got the paper completely coated this time, I suspect they will show as areas of reduced or uneven sensitivity.
So... Pdeeh's post made me wonder what's changed. These last 4 were salted with 1/2% citric acid in the salting solution. That's the most obvious thing that has changed, and I wonder if that could have changed the surface of the paper. Or maybe the humidity is different, since these salted papers have been stored between blotter for several months. Or maybe my hake brush is changing over time. Whatever it is, I'm never going to try to coat the paper under my weak dark red safelight again!
I made a calotype + salt print for MSA, and the calotype has some bad stains on it. But I was a little disappointed that the most glaring problems in the final print have to do with the salt print and not the calotype. I just looked back through a stack of salt prints, about 40 of them, and it is obvious that my problems with coating have gotten worse over time. The last 4 are by far the worst, with streaks and sections left uncoated or weakly coated. My first dozen were very evenly coated with almost no streaks at all except around the edges.
So, just now, I decided to try another, and I closed the blinds in my study, turned on an incandescent light, and sat at my desk where I could see. Well, it was obvious what's been happening. The AgNO3 solution is simply not going onto the paper as smoothly as it used to. The brush is leaving streaks of uncoated paper. Under the safelight, these were too hard to see. Even though I got the paper completely coated this time, I suspect they will show as areas of reduced or uneven sensitivity.
So... Pdeeh's post made me wonder what's changed. These last 4 were salted with 1/2% citric acid in the salting solution. That's the most obvious thing that has changed, and I wonder if that could have changed the surface of the paper. Or maybe the humidity is different, since these salted papers have been stored between blotter for several months. Or maybe my hake brush is changing over time. Whatever it is, I'm never going to try to coat the paper under my weak dark red safelight again!