Widely used as a color-forming agent in thermal paper coatings, this chemical enables image development when heated, commonly found in receipts, labels, and fax papers. It works by reacting with a developer compound upon exposure to heat, producing a visible color change. Its sharp color transition and stability make it ideal for high-quality thermal printing. Also utilized in carbonless copy papers and pressure-sensitive systems where color development is triggered by physical pressure or heat. Due to environmental and health concerns, some applications are shifting toward alternatives, but it remains prevalent in various thermal recording media.