The base paper for computer printing is called carbonless copy paper, which is divided into upper page paper, middle page paper, and lower page paper. On the lower side of the upper and middle pages, there is a drug applied, and on the upper side of the middle and lower pages, there is another chemical drug applied. After being combined in the order of top, middle, and bottom pages, when subjected to the impact force of the printing needle or the pressure of the pen tip, two different drugs will meet and show brilliant marks, thus achieving the purpose of copying.

The upper paper is called CB paper, and only the lower side coated with CB drug is called CB surface; The next page of paper is called CF paper, and only one side of it is coated with CF medicine and called CF surface; Medium page paper is called CFB paper, with one side coated as CF and the other side coated as CB. Carbon free paper dyeing is very important, and CB medicine is a coating containing capsules, binders, and additives. The capsule has a particle size of only 3-7 ц m, and the outer shell is made of resin. The interior is coated with solvent oil and contains colorless dye. 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 dye oil will flow onto the CF surface to cause the CF drug to develop color. CF drug is a coating containing colorants, binders, and additives, and the colorants are mainly certain resins and activated clay.

Simply put, the principle of color development on carbonless copy paper is that microcapsules are compressed and react with CB and CF drugs to produce color. In actual production, the next and middle sheets are produced in the same large coating machine, while the upper sheet is produced in a small to medium-sized coating machine.

What are the benefits of carbonless copy paper? Benefits of carbonless copy paper:

1. 1. No need to pad with "carbon paper". Direct writing is convenient and time-saving, with 2-6 pages of duplicate copies and 2-10 pages of electric printing, greatly improving work efficiency.

2. 2. The copy has clear and distinct handwriting, does not fade, and can prevent alterations or imitations.

3. 3. Will not dirty fingers, clothing, and other stationery, clean thoroughly.

4. 4. It comes in various colors and is easy to identify and process.

5. 5, The paper is of excellent quality, with a smooth and smooth surface. It is stronger than 28 grams of colored paper, less likely to be damaged, and has bright printing colors.

6. It does not contain harmful raw materials or odors, is safe and reliable, and the graphics and text on the paper can be stored for more than 15 years after color development.

Carbonless Paper Classification

CFB：48g/m2 、50g/m2、52g/m2；

CF：44g/m2 、47g/m2、77g/m2.

According to the color of the paper, there are five types: red, yellow, green, blue, and white; According to the color scheme presented, there are colors such as blue, yellow, orange, black, and red. It is precisely because there are so many types of paper that carbonless paper can achieve the effect of multi copy replication.