This is packed into a small, almost airtight, rectangular tin, then heated slowly and steadily over coals for a long period of time, allowing it to undergo thermal decomposition (aka, pyrolysis).

The material that remains after this process is complete ignites very easily, making it the preferred tinder when lighting a fire using flint and steel.

Applying the same principle that has been used throughout history by indigenous peoples, char cloth can start a fire with only the help of flint and steel, it is then placed in a tinder bundle and blown into flames.

'The hard flint edge shaves off a particle of the steel that exposes iron, which reacts with oxygen from the atmosphere and can ignite the proper tinder'.

One of the earliest recorded uses of a char cloth dates back to a ninjutsu manual written by Hattori Hanzō in 1560 called the Ninpiden or Shinobi Hiden, or Legends of Ninja Secrets.

"[8] The production of char cloth occurs when organic cellulose based fibres undergo pyrolysis, an irreversible chemical reaction that includes the thermal decomposition of material in an inert atmosphere (in the absence of oxygen).

"Biomass is a complex material, mainly composed of hemicellulose, cellulose, and lignin in addition to extractives (tannins, fatty acids, resins) and inorganic salts".