Thermal paper is a special paper type that is manufactured with specialty coating that aids in inkless printing. On application of heat to the coating, a clear image is formed on the paper with no requirement for ribbons or inks. The coating usually turns black on heating, which, in turn, transfers the image to the paper. Thermal paper is the key component of thermal paper printing, which is considered one of the most economical printing technologies owing to its low energy consumption and low maintenance cost.
Techopedia explains Thermal Paper
Thermal paper is composed of a base paper, an undercoating and a thermal coating. Both coatings are provided on the same side of the paper. The thermal coating helps in the printing process, whereas the undercoating helps in improving the base paper to suit it for printing and help in creating a smoother and high-quality finish. Sometimes additional coating is also applied on the paper for protective purposes. Based on the composition of the principal characteristics, different quality types of thermal papers are available.
Reliability, durability and high-definition images are characteristics of printing on thermal paper. Printing on thermal paper is faster than other modes of printing technologies, and this helps in high-volume printouts. Again, the printing involved is quieter, and so high-output printing is a smooth experience. The print images on thermal paper are of high quality and are also capable of handling high-quality barcode scans. Apart from being economical and low in energy consumption for the printer, thermal papers offer great flexibility with respect to size. Different formats of printing are supported by thermal papers. The images do not fade or smudge over time and last for a longer period of time. Another advantage of using thermal paper for printing is the low maintenance cost as there are fewer movements involved in such printers.
For these reasons, the technology is used in various sectors such as health care, retail, etc. It is also used in most transaction documents, point-of-sale receipts and some faxes.