Rather than use paper for a shim to keep the batteries from rattling/missing contact. Try plastic! Plastic will not absorb moisture like paper might.
Cut several (maybe a half dozen) strips from an old milk container, about 1/4" to 3/8" wide, and about 1/4" shorter than the total length of your batteries.
Insert them between the batteries and the case of the flashlight.
Insert as many as needed to get a snug fit, and no rattle; and, save the others in case you need more for different batteries, or flashlights.
The extras take up no room in the bottom of any bag, and are there if you ever need them, or, drop the others while changing batteries.
Cheap, effective, and ZERO cost! And, you know where to get more for yourself or friends!
Another tip - a little dab of dielectric grease on the contact points of the batteries, and on the threads of the flashlight metal parts, will keep corrosion at bay, and promote good contact. It only takes enuf to put a slight film on things. Dielectric grease is available at almost any automotive parts place, available in small tubes as "tune up grease." Great stuff for electrical connections.
Last edited by Wanderer; 10-26-08 at 11:37 AM.