Flash paper is a material that, upon ignition, burns up with a bright light. It is small enough to fit comfortably in a magician's hand.
To activate flash paper, a heat source--such as a lit match or cigarette--is applied directly to the paper. The flash lasts a few seconds before turning to a small bit of ash. Magicians will also use hidden devices to activate the flash.
Flash paper is a form of nitrocellulose, a compound found in gunpowder. As such, special care is required when handling the material.
Stage magicians often use flash paper during their acts. The paper is used as a distraction during unrelated tricks. Or, when mixed with a quick hand, flash paper is used to make items vanish.
As it requires less heat, flash cotton can be used in place of paper, making for a safer method of fire magic. A spark is all it takes to ignite the cotton.
Flash paper gained renewed prominence when it was used on the American television sitcom "How I Met Your Mother" by actor and magic fan Neil Patrick Harris.