Hugh,
Caution. My dad stored several mason jars around the property stuffed with $100 bills rolled tightly. When he moved from the old homestead, we helped him dig them up and found mold had invaded the jars so the outer eighth inch of $100 bills turned to dust. The bills were in so tight we had to break the glass to get them out. We will never know how much was lost, but if i were doing the same thing today I think I might look at vacuum packing to insure survival. – M.