Flash paper is mostly used to ignite dyes or reactive coatings in riskless demo setups

https://beckettxujn546.capitaljays.com/posts/sixty-five.-flash-paper-for-small-pyrotechnic-style-visuals-non-explosive-focus

Flash paper is sometimes used to ignite dyes or reactive coatings in reliable demo setups. The brief flame can provide a controlled warm pulse for transient reactions.