The principle of 58mm Thermal Printer is that a transparent film is applied to a light-colored material (usually paper), which is heated for a period of time and then becomes dark (usually black, Fiscal Thermal Printer). The image is formed by a chemical reaction in the membrane by heating. This chemical reaction takes place at a certain temperature. High temperatures will speed up the chemical reaction. When the temperature is below 60℃, the film needs to go through quite a long time, even several years to become dark; At 200 ° c, the reaction is completed in microseconds.

The Thermal Printer Factory selectively heats the thermosensitive paper at certain positions, resulting in the corresponding graphics. The heating is provided by a small electronic heater on the print head in contact with the thermosensitive material. The heater arrays are logically controlled by the printer and, when driven, produce a pattern corresponding to the heating elements on the thermal paper. The same logic circuit that controls the heating element also controls the feed, thus printing patterns on the entire label or paper.

The most common Thermal Kiosk Printer use a fixed print head with a heated dot matrix, with 320 square dots of 0.25mm by 0.25mm each. With this dot matrix, the printer can place the print point at any position on the thermal paper. This technology is already used in paper printers and label printers.