How to flatten 35mm film strip
I have a Pakon MM-100 slide mounter that likes to consume my film. It demands two or three frames as a sacrifice to its voracious appetite, on average, from each 36 exposure roll. Even one, of course, would be unacceptable.
I don't think there is anything wrong with the slide mounter itself, except perhaps for the design of the gate area where the cut film is inserted into the slide mount.
The mounter does fine when the film is flat, but it misfeeds and mismounts and/or completely destroys a frame of film every so often if the film has an arch of more than a couple of millimeters down the center of the film strip between and parallel to the perfs. I'm pretty sure if I can get my film to lie flat, it will not misfeed and get eaten by the slide mounter.
I process my film in a Jobo and hang it up vertical to dry with a weight on the bottom. Some film seems to dry flat and causes me no problems. I've had no problems at all with Koday EPY 64T. The Fuji Provia, however, always seems to dry with a significant arch to it, and is at greater risk of a misfeed.
I've tried rolling the film in both tight rolls and loose rolls overnight after drying to make them flat, but it doesn't seem to help. A tight roll is bad because it will also put a curl to the film that can also result in misfeeds.
Have any of you encountered this sort of problem with your slide mounters, or do you know of a way to safely flatten the film long enough to get it through the mounter without incident?
Might it be a humidity issue?
My 35mm film strips curled horribly when kept in a very dry environment. I recently moved them to a more humid place and they flattened on their own accord. Of course, you don't want to have too much humidity. I now use a dehumidifier with programmable presets in my workspace. I aim for 50-55%, though if anybody more knowledgeable can recommend a more appropriate level, I'm all ears.