I’m not sure if this is the right place for this; if necessary, just move or delete it:
I’ve found that fluff and small fibres come loose from the light-sealing strips on the new plastic film canisters (e.g. Adox Silvermax) and end up sticking to the film. This happens on the emulsion side too, which then affects the exposure. Attached are two images from a Silvermax film. I’ve noticed this on several Silvermax films. You might want to keep an eye out for this.
(The images aren’t very clear; it’s more obvious in real life and in colour...)