Materials Needed
100% Cotton Cloth cut into One to two inch squares
Tin Can with lid
Fire

Cut cotton cloth into squares approximately one to two inches wide. An old t-shirt works very well.  You can also try blue jean material, gun patch material, or cotton rope strans.  The key is the material should be 100% cotton.

Place a few cotton squares or material loosely in a tin can. An old tin shoe polish can works great, Or you can purchase a quart paint can from the hardware store. Make sure the lid has a hole to allow the gases and fumes to escape.

Place the tin can on a fire source. A charcoal fire works well when at home. A good fire with a lot of coals works well when camping.

A flame will come from the hole on the top of the tin can. Let the flame burn until it goes out. The cotton cloth in the can should be charred.  You may need to experiment with how long to leave the can in the fire. The smoke is the best indicator and you should not leave it long. Char that is left too long on the fire will not cacth the spark well.  Also if you do not leave it long enough it will not work.  Brown spots on the cloth is not what you want to see.

Keep your charcloth in a tin can for safe keeping.