I would think that mason jars, over time, with corrosion... would loose their seal when outdoors. A tupperware type container is very common but I don't know about the seal that much. One way I hear of a lot is that people use tupperware or rubbermaid stuff and put a ziplock bag inside. That gives you double protection.

I thought of the idea of putting matches in caches as I have a lot of them that I have harvested over the years. However I have a little uncertainty of that as I would hate to hear of someones cache being torched by some idiot with my matches. Or god forbid some fire started in the woods ... That was just my feelings though.

I was thinking of creating a few caches myself and this is what I had thought of.

PVC tubing. Select a nice size diameter and cut them about 12" long. Then,using various fittings... put a piece of clear plexiglass on the bottom. This would allow someone to see inside without opening it. I was concerned with the design that it might resemble a pipe bomb or something. I have read some stories, here in the Chicago area, DuPage County actually, on BBs etc. about people who have had their caches taken by forest preserve rangers etc. There seems to be a sensitivity to abandoned boxes... after 9/11. If you use a clear box, or design a capsule that can be looked into without opening you can eliminate or at least reduce some of that anxiety. Also paint or label your cache clearly that it is a GEOCACHE. On the other end I would put a cap that can be removed. I believe there are fittings with screw on covers for drain cleanouts... that might be good. Also, I used a piece of PVC for a fishing pole once, for travelling on an airline. For that there were some simple caps that could be used also. Use some caulk or bathtub sealer around the plexiglass, inside and out and seal off as many seams as you can. That should help with most weather. For added protection though, use ziplock bags inside and check your caches periodically for their condition. Also you might not want to hide them on the ground if in a floodable area. Maybe select a height of about 3 to 5 feet or higher if possible. My innitial preference is to use the screw on clean out with a washer or o-ring if something is available.

I have no idea of cost on this but it just seemed a good sturdy and durable capsule. I might have to reconsider if it gets too costly.