I have conserved a number of these WWII printed maps on silk, all belonging to the families of the airmen who had them sewn into the linings of their jackets, all printed maps of the areas over which they were flying should they get shot down. Since the families wanted them displayed, they were humidified, and flattened prior to mounting. When necessary torn areas were repaired with sheer fabrics or threads impregnated with archival adhesive. Although the sharp fold creases were in evidence, none of them arrived at my studio folded. The most recent one arrived torn and still glued to its cracked and distorted mat frame.