"Anton Shepelev" wrote in message
...
On 2010-02-12 18:59:24 +0300, "Richard Knoppow"

There was a sort of generic print flattener formula,
about 60 ml of glycerine per liter of water. Soak the prints
in this for about five minutes after washing. Then squeegee
off the excess and dry. Hydroscopic flatteners like this are
frowned on by conservators because they can promote the
growth of mold on prints. I've used various print flatteners
but not found any to be completely successful. I generally
flatten prints using a dry mounting press. Those seem to
stay flat permamently.

Richard,

I don't quite know what a mounting press is. Do you mean
you keep your films flat under a constant heavy pressure?
How strong is that pressure? What kind of sleeves/packaging
do you use for films stored this way?

For what it's worth, what has worked for me well through the years is a
50-50 mix of denatured alcohol and water. Take a damp cotton swab of this
mixture and swipe it across the back of the print. Then place the print
face down under some moderate weight overnight - a couple of books will do.
In the morning, the prints are satisfactorily flat.