The upper paper is called CB paper, and only the lower side coated with CB medicine is called CB surface; The next page of paper is called CF paper, and only one side coated with CF medicine is called CF surface; 

Middle page paper is called CFB paper, with the top side coated as CF and the bottom side coated as CB. Carbon free paper dyeing is very important, as CB drugs are coatings containing capsules, binders, 

 and additives. The capsule particle size is only 3-7 ц m. The outer shell is made of resin, and the interior is coated with solvent oil containing colorless dyes. When the capsule is damaged by external force, 

the dye oil will flow out. If the CB surface is attached to the CF surface at this time, the carbon free copy paper will have the dye oil flow to the CF surface, making the CF drug appear more brilliant. 

CF drugs are coatings containing colorants, binders, and additives, and the colorants are mainly certain resins and active clay.

The functional characteristics of carbonless paper are that the front of the upper paper can be copied when it comes into contact with the front of the middle paper and the front of the lower paper. 

Two sheets of upper paper or two sheets of lower paper cannot produce a copying effect.

Carbon free copy paper does not require colored wax coated copy paper, and can be copied without wax coated copy paper due to the use of chemicals. Multiple pages of carbon free paper can be stacked 

together and printed or written directly to create multiple copies of the document. It is convenient for cleaning and can also be made into perforated blank computer printing paper, achieving continuous 

printing and copying. The production of carbonless paper base paper is very important.