Once you've taken care to keep your antique documents away from acid-ridden backing, sunlight and humidity, wrinkles are the biggest enemy. Bent edges and permanent creases devalue documents, even those with purely sentimental value. That said, a few simple actions can keep them from becoming even more damaged. If you have a large number of antique documents to store, such as a photographs, place them in a photo-safe box with sheets of acid-free paper between them. If you have photographs or documents that will be handled occasionally for viewing, store them individually in plastic sleeves or pockets made specifically for heirlooms. Really long documents, such as deeds, may be stored safely in cardboard cylinders.
And, you can always print digital copies of your keepsakes. That way, not only will you have an archive of the originals, but you can take off the kid gloves for a change.