With thermal paper, if you want to print text or graphics on its surface, you need special printer cooperation, which is thermal printer. If you have the opportunity to dismantle the thermal printer, you will find that its internal structure is very simple: there is no cartridge, the main components are the drum and the printer head. Thermal paper used to print receipts is usually made into thermal cash register rolls. When a roll of thermal paper is put into the printer, it will be driven forward by the drum and contacted with the printer head. There are many tiny semiconductor elements on the surface of the printing head, which can heat the specific area of the paper according to the text or graphics we want to print. At the instant of contact between the thermal paper and the printing head, the high temperature produced by the printing head causes the dyes and acidic substances on the surface of the thermal paper to melt together into liquid and react biochemically. Thus, the text or graphics appear on the surface of the paper. Driven by the drum, a shopping receipt was printed out.

Why do businesses firms use thermal cash register rolls and printers to print shopping receipts instead of laser or inkjet printers, which we are more familiar with? First of all, laser or inkjet printers need complex devices to transfer ink or toner from printers to paper. These two printers are large in size and usually need AC power supply. Businessmen often need smaller printers, especially when selling goods outdoors or on airplanes or trains. It is obviously unrealistic for a printer to print receipts for customers. Secondly, the replacement of cartridges or toners by laser or inkjet printers is often time-consuming and laborious, which is also very unwilling for businesses and consumers if it delays customer checkouts.

These problems can be solved by replacing laser or inkjet printers with thermal printers and thermal cash register rolls. Since ink has been pre-stored on paper, thermal printers no longer need complex structures to store and transfer ink, they can be very compact. And it can be battery-powered, very suitable for merchants to carry, especially in the outdoor or transport for customers to print receipts. Because of its simple structure, the thermal printer is easy to maintain. Users do not need to worry about replacing ink cartridges, as long as a new roll of thermal paper is quickly replaced when the paper is used up, which ensures that customers will not delay too long. In addition, the thermal printer printing speed, low noise, is very suitable for use in shopping malls. Because of these advantages, thermal printing is not only the preferred way to print shopping receipts, but also often used to print tickets, labels and even faxes.