To understand how thermal paper displays text, let’s first talk about the structure of thermal paper. In fact, thermal paper can be divided into three layers according to the different chemical properties of each layer. The bottom layer is called the paper base, which is the ordinary paper after a certain surface treatment, in order to prepare for the attachment of thermal substances. The second layer is the thermal coating, this layer is mainly a collection of various chemical substances, can be subjected to heat after the color. The last layer is the protective layer, which is used to protect the text or pattern from external damage.

In fact, thermal paper is mainly composed of three components: colorless dye, color developer and adhesive. At normal room temperature, none of these three components will react chemically. However, when the thermal paper meets the heated print head, the colorless dye reacts chemically with the color developer so that the text we see can be rendered.

And the information displayed will be blue, black, purple and other colors depending on the colorless dye, which is why you will receive small tickets with different font colors.

But did you know? In fact, thermal paper also has disadvantages.

Although thermal paper can be found everywhere in life, the disadvantages of thermal paper are also obvious. While using thermal paper, we often find that after a period of time, the text on the thermal paper becomes blurred or even turns into a blank sheet of paper. Have you ever seen such a situation?

In fact, such a situation is very common in our lives. After a period of time, the text on the thermal paper magically disappears. This is due to the fact that the text and other information on the thermal paper comes by chemical reactions, and these chemicals are often not very stable. Therefore the printed out small ticket will then be lower and lower over time until the font disappears. So if the content printed is very important, it is still recommended not to use thermal paper for printing.