Me too. I can only relate my experiences. What I did, about 3 years ago,
was to cut them into strips of 5, put them in archival sleeved pages and
stored them flat with a weighted board on them. At present, when removed
from the sleeves, they still curl, but not severely, and can be handled
easily for enlarging. Some of us and an instructor at a photo lab tried
soaking some in photoflo solution and hanging them for a week, however that
did not seem to do much. It seems to me that reverse curling, unless done
extremely carefully could lead to scratching.
Things not to try are ironing, torches and bad advice.
"Jan Philips" <email@example.com> wrote in message
news:firstname.lastname@example.org...> I've got some 35mm negatives from 20-25 years ago that I never cut,
> and I rolled and put in film canisters. (I know, I shouldn't have
> done that.) Now they're pretty curled. Is there a good way to
> flatten them out?
> (right now I'm experimenting with rolling one the other way for a