You need to saturate the cotton. This is easier by warming the petroleum jelly. Then you squeeze out -and squeeze again all the excess vaseline. Try puttig it in a plastic bag and roll with a can. When the cotton looks like an untreated ball, only with a slightly greasy feel it's almost ready. Now gently "fluff" the ball by carefully pulling the fibers. think about your cotton tinder as- tinder! A glob of vaseline, while flammable is like the large billets of wood in your fire's final construction. Remember too, when making fire with sparks work close with your materials.