Even dry cotton as long as you're fast. I often use dry cotton with small ferrocerium rods. Catches with the teeny tiniest of spark and will burn for about ten seconds and if you prepare your fire ahead of time properly then ten second is more than enough time. The big downside however is trying to acomplish this in wet conditions. Having your tinder burn as long as possible is certainly advantageous in wet weather. <img src="/images/graemlins/grin.gif" alt="" />