I have never thought of kydex but you are right you could do that, however you can not cook in it. That would work in a Desert environment. 
mcse,
Since the original post has to do with Altoids sized tins I thought you were looking to make a container similar in size.  I didn't know you were looking for something big enough to cook in.  In fact, when I first read your post quoted above I had a vision of somebody holding an Altoids tin over a fire and trying to cook that squirrel they trapped.  <img src="/images/graemlins/grin.gif" alt="" />
Robert