I have loved the heavy duty rubber bands cut from inner tubes since I first read about the idea on this forum. It never occurred to me that they would work very well to waterproof an Altoids type tin when cut to the correct width, but that makes a lot of sense.<br><br>And yes, I agree. If I kept supplies that I'm likely to use often in my PSK, I would not seal it up like I do. But, I'm one of those guys who keeps first aid & medical supplies separate from fire/shelter & water/food supplies. My first aid tin is dedicated to that task alone, and I have never sealed it up. I keep it open so I'm encouraged to use it at the first need of any of its contents. My PSK I keep taped as I described earlier, then wrapped with cordage. My preference is that the act of opening it should be difficult, since I feel it should be a ritual "declaration" by which I announce... to myself, if no one else... that, yes, it has now officially become an "emergency". It can't help but be a focusing tool and an attitude adjustment that way.<br><br>So thanks for the idea of using the rubber bands for waterproofing! That'll be a great way to seal my first aid tin against water! Up until now, my first aid tin has just not been waterproofed at all, since the only way that had occurred to me was taping. I love getting good ideas from the people on this forum!