Offset printing, offset printing is a kind of lithographic printing, and its engraving is basically flat.

Traditional offset printing is an indirect printing method, that is, the printing plate and the paper are not in direct contact, and it is still widely used in the banknote printing industry, mainly used to print auxiliary coins such as RMB small main currency and diagonal cent coin.

Offset printing is the use of the principle of oil and water repulsion to make plates, first grinding plate processing, on the bright metal surface on the emery, magnetic balls, grinding with a grinding machine, after the layout hair, it is easy to absorb water, and then coated with a layer of offset printing solution, it forms a very thin, very uniform water film on the surface, and the ink is oily, the ink can not be stained when the ink is played. After grinding the plate treatment, the plate making begins, after a series of development and exposure treatment, a layer of film can be formed in the place with the pattern to absorb the ink, and the place without the pattern will not stick to the ink due to a layer of water, so that the offset printing plate is made. When printing on the machine, the ink of the pattern part is transferred to a piece of rubber, and the pattern on the printing plate is printed through the contact between the paper and the rubber.

There is a big difference between the offset printing used in the banknote printing industry and the offset printing in the ordinary printing industry. The biggest difference is that in the process of photographic plate making, ordinary offset printing adds a layer of mesh after color separation, and the mesh plate is made before printing. In this way, the patterns it prints are made up of small dots. The offset printing used for banknote printing is composed of continuous straight lines. There is also a big difference in ink. Generally, color offset printing uses yellow, red and blue three-color inks without other colors of ink; There are many colors of ink used in printing money, and you don't need to mix colors, and you can use whatever color ink you print.

Flat embossing, the banknote printing industry of flat embossing is mainly used for wiring technology and belongs to the scope of flat printing. Its printing plate is basically flat, and unlike offset printing, its pattern part is convex, slightly higher than the plate plane. Flat embossing uses the method of chemical corrosion to make plates, and uses chemical chemicals to corrode the parts without patterns, leaving the places with patterns to bulge to form letterpresses. The printing process is similar to offset printing, it is first through an ink cylinder and letterpress contact, so that the convex place is glued with ink, and then the convex place is glued with ink, and then the ink of the embossing plate is transferred to the rubber, and then printed onto the banknote paper.

Gravure printing: Gravure printing, referred to as gravure printing, is the traditional method of banknote production, and now banknotes around the world are still commonly used in gravure printing. The inking part of this printing plate is concave, and the printing plate is directly in contact with the paper surface during printing, and the ink in the concave is directly transferred to the paper under strong pressure, and the ink presents a three-dimensional state on the paper, and there is a feeling of unevenness when carefully touched by hand. Gravure printing is divided into deep and light prints. The concave degree of the original engraving of the deep pattern is deep, and the three-dimensional sense of the ink is strong; The original engraving of the light plate is shallower, so the degree of ink convex is also relatively shallow.

In the 21st century, two characteristics of gravure can be easily found on paper coins, one is that the ink layer is thick and the feel is strong; Second, it has a strong three-dimensional effect.

The plate-making method of gravure plate is very complex, and it generally has to go through the following processes: first, the original plate of small steel is pressed into a certain specification of plastic letterpress that meets the requirements by hot pressing, such as 1 yuan coupon printed on 40K paper (that is, 40 pieces of 1 yuan coupon should be printed on each sheet), then 40 small plastic letterpress plates should be pressed with small steel original plate. Then the electroforming method is cast into a copper plate of the same size as the plastic plate, and then this copper gravure is used to turn out a nickel letterpress of the same specification, and finally an iron gravure plate of the same specification is turned out, and after these production processes, the printing plate used on the gravure printing machine is formed. In the inking process of gravure plate, the whole plate needs to be coated with ink, and then the part of the ink without the pattern is wiped off with water, and only the part of the ink with the gravure pattern is retained, so that about 80% of the ink is wiped off, so the cost of using the gravure method is quite high, except for the banknote printing industry, other printing industries generally do not adopt this printing method.

Gravure printing According to the different ways of plate making, gravure plates can be divided into manual engraving and machine engraving gravure plates. The main parts of hand-engraved printing are portraits, landscapes, line names, ethnic characters and face values; Machine engraving plates are mainly used to print relatively regular patterns, such as lace, bouquets, etc.

The hand-engraved version of the portrait is exquisite, which is not only a high-end work of art in itself, but also has the important characteristics of banknote printing and anti-counterfeiting. Because each engraver's work has its own personal style and characteristics, which cannot be imitated by others. Although there are many advanced replication technologies and counterfeiting methods in the world at present, but can not reproduce the banknotes that are exactly the same as hand-carved works, in today's more developed science and technology, anti-counterfeiting means are becoming more and more advanced, hand-carved gravure is still a common anti-counterfeiting measure in the world. Hand engraving is one of the most critical aspects of printing banknotes, and it is the most difficult to make mistakes. The tool used in hand carving is not a knife but a pen, and the plate of the steel plate is softer than the ordinary steel plate pin. When working as an engraver, you must hold a magnifying glass in your left hand and a pen in your right hand, and depict it on the steel plate with a calm heart. Someone once calculated the dots and lines on a banknote, and a point had to be carefully carved with several knives, and a banknote meant a million knives to be engraved. If there is no endurance to sharpen a sword for ten years and excellent basic skills, ordinary people will never be able to do this.

Letterpress printing: Letterpress printing is referred to as embossing, the inking part of this printing plate is convex, the convex part is coated with ink, and the pattern is printed directly on the paper, similar to a stamp. Due to the heavy pressure between the printing plate and the paper surface during printing, the back of the paper will be dented, and the edge of the line will sometimes squeeze out the ink due to the large amount of ink.

Embossing is mainly used to print the serial number of banknotes, the length of the seal, etc. When the embossed pattern is higher than the plate plane, the printed pattern is lower than the paper plane, as if pressed into the paper. Although the plate pattern of flat embossing is also higher than the plate plane, its degree of elevation is much smaller than that of embossing.

After careful consideration, Mei Xiaohan decided to use the method of hand-carved gravure printing to print banknotes, and find a production company, as long as you are willing to spend a lot of money, there is no problem if you want to print it.

Mei Xiaohan has thought twice about the fact that the production company may be suspicious of this problem, he knows that the banknotes he produces are different from any country or region, and it is impossible to enter other countries and markets, except for exquisite handicrafts, these banknotes will be useless.

Although the number of banknotes issued should be considered according to the market, but between the relationship of printing conditions, Mei Xiaohan decided to print a large number of these banknotes, as for how to put them on the market in the future, it is not yet said to be considered.

This time he crossed the country, and the task was even more difficult, he had to print all the currency that a country would need in the future.