I have various tinders vacuum sealed into 3"x4" mylar bags. The pouches are very very sturdy; I've sent a few to some fellow ETS'ers and none of the packages have failed so far as I know. I make up little micro-kits by using about a 2" x 2" square of Tinder Card- this stuff is awesome. It's stiff so it makes a great backer and it burns like a candle. A 1/4" x 1" strip will burn for about a minute or so. You can score it with a knife and light it with a spark if need be. Generally I will set one x 4gram ESBIT tablet on it along with four or five Tinder-Quiks, then seal it up. The mylar keeps it all dry and has a zip-lock so you can open it and reseal what you don't use.

Occasionally I'll make a slightly more deluxe version with a few matches or even a Spark-Lite sealed in with the tinder.