fiber paper in my darkroom when dried does not seem to curl much. Maybe it is humidity. I don't have a humidity meter. I would think that in cold dry climes the paper would tend to curl more. A dry mount press is important none the less. One thing I find important when finishing the wash process is I take all the prints that day and one at a time I squeegee front and back on a heavy piece of glass then I lay the prints face down on the fiberglass screening. Then I don't fool with them until dry. I generally try to do that when I am done for the day or session so the temptation is gone when I am not there. There is a slight curl towards the emulsion when dry. At least that is how it is in my darkroom.