One of my favorite methods is simply to take a hot iron without any steam (you don’t want the steam to damage the print). Place the print between two sheets of plain kraft paper or other clean paper without any printing on it. Experiment with a lower temperature at first and be careful to not burn your print by keeping the iron on it too long. Keep the printed part face down so the inks are not directly exposed to the heat. The idea is to warm up the print in the process but not to cook it. I have heard of a lot of artists and photographers using this method so I tried it once myself. It worked out great. It also works well on unmounted canvas prints which have been creased during handling.

The bottom line is print curling can be fixed. They will eventually flatten out on their own since they are no longer under the pressure of being rolled. There are also plenty of YouTube videos out there with great suggestions to fix the curling as well.