In the colder winter months, starting a fire reliably can spell the difference between life and death. This means that you'll need a reliable ignition source, such as matches, a ferrocerium rod, or a lighter. It also means that you'll need tinder that will take a flame quickly, and burn long enough to ignite the kindling wood. One excellent type of tinder for survival situations is known as char cloth — if you're not familiar with it, check out our previous post on “How to Make Char Cloth Fire Starters”.
The traditional method for making char cloth involves a metal tin, typically with a small vent hole punctured in the top. The cotton or jute material is placed inside the tin, which is positioned near the base of the fire. Over the course of 10 to 15 minutes, the heat causes the cloth inside to blacken or char into a highly-volatile tinder material. This method works well, and we've used it many times.
However, what happens if you don't have access to a metal tin? Perhaps you have a tin but don't want it punctured and covered in soot, or maybe you didn't bring one with you in the first place. The following video from Sharp Works shows how to make char cloth in aluminum foil:
The biggest advantage to this technique is that aluminum foil is very lightweight and compact. Folded into a small square in your pack, it will take up far less room than a hard metal tin. Also, aluminum foil can be re-purposed into a container for cooking food or boiling water.
Ideally, you'll want to find some commercial-grade heavy-duty or extra heavy-duty foil, as it will be slightly thicker than the ordinary kitchen variety. This will improve durability, and allow re-use of the same foil multiple times. Even if you don't need it for char cloth, aluminum foil is a great tool to have.