The working principle of thermal paper is putting particles of powder on the common paper whose ingredients is leuco dye phenols or other acidoid, they are divided by thin film, in the heat, thin film will melt with powder, the reaction between them causes words on the paper are unstable, they are faded easily. The common lottery is made of thermal paper. The common thermal printer paper is not suitable for long-time storage, but thermal printer paper with good quality can be stored for more than 30 years.

Thermal paper is used as the printer paper for thermal fax machine and thermal printer, its quality plays an important role in its quality and retention time, even it will influence the service life of printer and fax machine. At present, thermal printer paper in the market is with different quality, there is no standard for it, many users don’t know how to choose good thermal paper, it is convenient for some merchants to produce thermal paper with bad quality so that users may get thermal paper with short retention time and vague words, what’s worse, it is harmful for printers.