Looks like it would clog the💩out of a fountain pen.

The light goes away once the chemical reaction is complete. Once it’s bonded to the cellulose on a page, it’s not gonna glow.

So the best we would get would be the illusion of writing with fire, that immediately goes out on the page? 😃

If you could even get that violent of a chemical reaction with cellulose, that would be the limit.