This is one of those techniques that I love and the effects are outstanding, but please when you try this yourself please please take care, I always do this in the kitchen near the sink! You need to take a piece of glossy card and a candle, light the candle and then with the glossy side face down pass the card backwards and forwards over the flame, move quickly and with the flame just touching the card. You will see the flame starts to coat the card in soot but not burn the card, take care near the edge of the card. Once you have a good coating of soot (you may need to do a few passes over each area) take a perfectly clean stamp and stamp into the soot, and as you remove the stamp you will see the stunning result. Take care not to scrap off any soot until you fix your piece, I use proper pastel fixative and put a generous coating off it down. I love the effect of this technique but please take care when doing it, and give your stamp a good scrub with warm water and an old toothbrush to get the soot off it!