Russ, I hadn't thought of the temp response of the humidity strips. Also, I am intentionally trying to force as much air out of the bags as possible. Even the paper in the test strip may be enough to influence the humidity of that small volume of air. The meter may also have some hygroscopic...
Good point, Russ. The humidity strips go from 10% to 60%, but I'm using them in conjunction with a meter. In effect, I am testing the strips as well as the storage method. They aren't readable with much accuracy, but I can easily include one of the strips in each film bag whereas it would be...
It's the paper!
The film has paper packaging which is hydroscopic and it absorbs more water at lower temps. Since the amount of water contained in the paper is greater than the water held by the small amount of vapor in the bag, it influences the RH more than the temperature. This property...
After leaving the bag out of the freezer over night, I placed it in a refrigerator. It was at 66.3F and 33% RH when I put it in and 34.2F and 26% RH a couple hours later. Now I'm wondering if the film in the bag is screwing up the results. Some months ago I had placed a desiccant pack in the...
Ah-ha! That makes sense. And I can test it by putting it in a fridge instead of a freezer. I should see the humidity go up, at least a little, if I don't let it get below 32F.
A very low humidity can cause film emulsion to get brittle, but this sounds more like the moisture isn't really...
I am working on a project to stockpile and freeze photographic film and paper for later use. This is not for academic or commercial purposes, but just for personal use. I've been experimenting and am stumped as t the following:
I place a package of film in a ziplock bag in an environment of...