Carbonless paper is a special kind of carbon paper, It is divided into upper page (CB paper), middle paper (CFB paper) and lower page paper (CF paper). which does not need to add charcoal paper between the paper, can be directly copied, directly colored, and will not stain fingers and clothes, making it more convenient and hygienic to use. The main feature of this paper is that it uses a chemical reaction to achieve a color development effect, rather than using coloring wax as in traditional carbon paper