This experiment involves setting fire to paper. The ‘ink’ contains an oxidising agent which when heated, provides more oxygen to keep the reaction going.
So you draw a design on the paper with a solution of an oxidising agent, let it dry and then carefully apply a glowing splint to one end of the trail. Watch as the glow and charring works its way along the message, leaving the untreated paper untouched.
Fire Writing – Risk Assessment