The original tape is generally composed of five layers, i.e. top coating, ink layer, inner coating, tape base and back coating.

1. Internal coating: it is mainly used to make the printed surface smooth and make the ink release from the tape base consistent.

2. Ink layer: the most important one, which is used to print and determine the use characteristics of carbon tape, such as chemical corrosion resistance and friction resistance.

3. Band base: it is the carrier of other layers and determines the performance of heat conduction.

4. Back coating: simply speaking, it is a special coating coated on the back of the carbon tape, and its main function is to reduce the wear of the print head; Reduce static electricity generation and enhance heat conduction.

5. Top coat: it is mainly used to improve the adhesion of ink on the label and enhance the environmental resistance. The front tape is generally transparent or other colors, and it has the following functions

1. Product identification: the product name, company name and trademark can be printed for marketing and sales promotion.

2. Protective function: used to protect the carbon belt.

3. Easy to use: it is convenient to put the barcode ribbon on the printer. Generally speaking, it plays a warning role, so that the printer can sense the end of the ribbon. Different printers determine different back tapes, and there are three main types:

1. Transparent: used for transmissive sensors, allowing light to pass through to indicate that the ribbon is used up.

2. aluminum plating (silver): mainly for reflective sensors, and the reflected light indicates the end of the carbon ribbon.

3. Used for mechanical sensing. The change of printer's induced tension indicates that the carbon tape is used up.