Using punk wood as a tinder is a great way to go about fire lighting. Punk wood is what’s left of wood after a dry rot has been through it. It’s one of those that you tend to find as you’re wandering around, often without deliberately trying to find it. It will ignite with a fire steel, traditional flint & steel, parabolic mirrors and lenses.
You can also char punk wood, which in my experience makes it easire to ignite.
You can see plenty of photos from all of these courses on our Facebook page.