Charcloth is material, usually 100% cotton, that has been cooked almost to the point of combustion. It is one of the best items to have on hand if you are trying to get a fire going. You can use it with any method of lighting (flint/steel, battery, etc.). Best of all, you can make quantities of it yourself in a short period of time and quite easily.
You’ll need a metal container, such as an old Altoids tin. Stick with something small until you really get the hang of this. You’ll also need your charcloth material. Pieces of denim from worn out jeans works well, as do cotton t-shirts. Cut or tear the material into small rectangles, a bit smaller than the inside of your metal container.
Punch a small hole in the top of the container using a nail or drill. Pile in your material, keeping it fairly loose. You don’t want to compact it down tightly. Close the container’s lid.
For your heat source, you can use anything from a propane grill to campfire coals. But you’ll need to do this outside as things will get smoky. Place your container over the heat and let it cook. The time this takes will vary depending on the heat source but after a period of time, you should see smoke start to come out of the hole in the top of your container.
After several minutes, the smoke should actually ignite and you’ll have a small flame coming from the hole. If need be, adjust the height of the container relative to the heat source, or adjust the grill burner setting, to keep the flame a few inches high.
Keep cooking until the flame dies out and the smoke begins to peter out. Remove the container and let it cool completely before opening. Properly made charcloth will be black and flexible. If it isn’t entirely black, you’ll need to put it back on the heat to cook longer.
When using charcloth, what you’ll do is throw sparks in some fashion onto the cloth. Those sparks should ignite the charcloth fairly quickly, though you’ll not see flames, just glowing embers. Move it to your tinder and gently blow on it to get the flames going.