First, paper

Anti-counterfeit paper is the material basis for printing various kinds of securities. Some special papers manufactured using special processes basically have security features. The anti-counterfeiting technologies used in special papers are:

1. Non-carbon paper is divided into upper, middle, and lower papers, and fine capsules are coated on the front or back surface. Both handwriting and computer prints are colored. It is generally used for the printing of various notes.

2. Watermark paper, watermark paper in the manufacturing process, you can use technical means to the required logo, pattern, etc. into the paper, these patterns are not easy to see in the ordinary circumstances, only to face the glare to see, China issued Most of the larger denominations were printed using watermark paper. Watermarks such as [Tiananmen] and [Mao Zedong] were produced in large-value RMB paper in China. In addition to being used in currency paper, watermarks have also been widely used in other ticket papers. The position of the watermark in the paper is fixed, not fixed and semi-fixed.

3. Thermal paper, paper surface coated with special heat reflected microcapsules. Hot print head printing is color, waterproof and non-waterproof.

4. Fiber paper, paper pulp mixed into the process but the multi-color fiber segment, the finished paper can be discerned. It can be seen that the monofilament or polychrome-linked fine fibers are "embedded" in the paper. There are also applications in some of the renminbi.

5. Safety thread, safety thread means that a gold thread or plastic thread is placed in the middle of the paper during the papermaking process. The earliest use of the security line was special gold wire. Now plastic wire has been used and it has been developed into various kinds, such as miniature letter security wire and fluorescent security wire. The shape of its security line is straight, wavy, zigzag, etc. China has adopted straight-line security lines in currency paper.

Second, security ink

The so-called anti-counterfeiting ink, that is, adding a special performance of anti-counterfeiting materials in the ink chain material, processed by a special process of special printing ink. It is mainly printed on tickets, product trademarks and packaging in ink printing. This type of anti-counterfeiting technology is characterized by simple implementation, low cost, good concealment, bright colors, easy inspection, and strong reproducibility. It is the preferred anti-counterfeiting technology for banknotes, tickets and trademarks in various countries.

1.Ultraviolet fluorescent ink can emit special visible ink (400~800nm) under the irradiation of ultraviolet light (200~400nm). According to different excitation light wavelengths, it can be divided into short-wave ultraviolet excitation fluorescence anti-forgery printing ink (excitation wavelength 254nm) and long-wave ultraviolet laser fluorescence anti-counterfeiting printing ink (excitation wavelength of 365nm). According to whether the color of ink can also be divided into two kinds of colored fluorescent ink and colorless fluorescent ink.

2. Light-activated color-changing anti-counterfeit inks, which can emit visible light (400 to 800 nm) in anti-counterfeiting printing ink under sunlight. This ink is discolored on the surface due to the action of the sun, and it is also substantially discolored by ultraviolet rays.

3. Thermal anti-counterfeiting ink (also known as thermochromic anti-counterfeiting ink), under the effect of heating, the ink can produce discoloration effect. According to the different temperature required for discoloration, can be divided into hand-temperature color anti-counterfeiting ink and high-temperature anti-counterfeiting ink.

4. Magnetic ink, using magnetic ink printing is an important anti-counterfeiting technology. Magnetic ink refers to the addition of a strong magnetic powder to the printing ink. This magnetic powder is both a colorant of the ink and can be evenly arranged in the magnetic field, and retains a high residual magnetism, so that the printed matter can see text and patterns with the naked eye. Magnetic recording information can also be read with a special instrument. The anti-counterfeit packaging of commodities, such as cigarettes, wine, and pharmaceutical products, can be printed on the production date of batches with magnetic ink-jet ink, and the manufacturer can record the special signals, and then can be identified by the magnetic signal recognizer to save the code anti-counterfeiting; coins, The anti-counterfeit of the ticket is a magnetic anti-counterfeiting mark such as RMB and checks. Magnetic inkjet ink makes magnetic security printing one of the most promising effective anti-counterfeiting means. Magnetic fluids will have greater development and broader prospects.

Third, the printing process

Engraving platemaking is an early anti-counterfeit printing technology with excellent results and is still applicable today. Hand-engraving plates are different because of their individual cutting methods, style, and uniqueness. Therefore, the depth, curvature, and angle of their engraving lines are difficult for others to imitate. This is because it is difficult for the same person to make two identical copies. With the application of high-performance computers and various special electronic drawing and publishing software, complicated, delicate, exquisite and high-resolution layouts produced by computers have emerged. This type of pattern is difficult to duplicate by artificial, photocopying or scanning, such as very complex flower, any geometric figure, single line, composite or twisted lace, or made in gravure, flat line relief, curved relief, multi-color relief Wait. Cluster flowers can also be embedded text, shading graphics can also be gradual transitions. In short, it is possible to create an unprecedented figure that is difficult to imitate despite the rich imagination of individuals.

Gravure Printing: The gravure image is lower than the printing plate layout, and the recessed pattern has a depth of light, so as to express the height of the graphic and ink, the thickness of the ink, so the printed pattern can be three-dimensional image, three-dimensional Strong, feels bumpy with your hand. China's 50 yuan and 100 yuan positive names, denominations, and Braille are all gravure. The frontal view of the fifth set of RMB 10 banknotes, Mao Zedong's head portrait, the “People’s Bank of China” name, denomination number, Braille denomination, and the backside view of the “Three Gorges” motif are all printed in engraving and gravure printing. .

Fourth, laser holographic image anti-counterfeiting technology

Laser holographic image security, also known as rainbow holographic anti-counterfeiting. It emerged in the early 1980s, has formed a new industry in foreign countries, laser holographic molding technology is a class of holographic grating technology in optics. It is a kind of holographic technology which uses laser holography principle to reproduce monochromatic or color images with white light, and it can quickly reproduce the entire process of imaging objects or map-level printing equipment and materials. Its products are not the same as ordinary photographs. It can not only reproduce the original image of the original, but also can show the different sides of the original with different orientations of the line of sight. From the similarities and differences between the reproduced image and the original color, rainbow holography can be divided into false color rainbow hologram and true color rainbow holography. The basic feature of the color rainbow hologram is to add a slit at a suitable position in the recording position system. Its role is to limit the reproduction of light waves to reduce the color blur of the image, thereby realizing the reproduction of white light with a single color or a color image.

Fifth, bar code anti-counterfeiting technology

Product barcodes are codes of commodities designed by humans for effective management of computers and other commodities. If we can reasonably use commodity technologies, including reasonable selection of the carrier of the barcode, a reasonable choice of printing methods and printing machines, a reasonable choice of the location of printing, etc., then it is possible to make the commodity barcode technology have an anti-counterfeiting effect.

At present, there are generally only two types of barcodes with anti-counterfeiting functions. One is invisible barcodes (covered implicit barcodes, invisible barcodes for photochemical processing, and invisible barcodes printed on invisible inks), and the other is a metal barcode.

Sixth, miniature

Microform: This type of anti-counterfeit principle is to reduce the height of Chinese characters to within 0.22mm, and the English character height is reduced to within 0.2mm. Microfilming is the simplest method to use in the layout design system and must be used in conjunction with other functions. Microfilming is characterized by replacing lines with words. A thin line, a closer look but found that it consists of words. Combined with the other features of imprint, you can make many changes to the text line. For example, a miniature Chinese-English intertwined text is arranged in an arc, which breaks through the single expression mode of the text tablet, which is full of changes and plays a role in anti-counterfeiting. This kind of anti-counterfeit means can be applied to documents and cards. Can be used to make micro-text shading, can also be used to make micro-letter micro. Another example is to use a set of texts to create smooth curves that are intertwined and intricately intertwined to form a group flower shape, exquisitely unique and varied. Microprinting technology prints the tiny text that can only be seen under a magnifying glass on a solid or dotted line. Of course, microtext can also be printed on the lines or dots that make up the diagram. Microfilm printing can be used for general tickets as well as security lines for banknotes or passport papers to integrate anti-counterfeiting. The fifth set of RMB50 notes adopts a magnetic miniature text security thread. The security line in the banknote paper and the light perspective can be seen in the miniature text “RMB50”. The instrument is magnetically detected.

Seventh, summary

In addition to the above anti-counterfeit printing methods, there are anti-counterfeiting stickers, special anti-counterfeiting printing of notes, encryption technology, laser holographic transfer paper technology, positioning hot stamping, telephone code anti-counterfeiting, nuclear dual-card anti-counterfeiting (nuclear track), etc. Again one by one. In short, modern anti-counterfeiting technology has developed into a comprehensive anti-counterfeiting phase, and a single anti-counterfeiting function has been unable to adapt to the development of the times and changes in the market. Users need anti-counterfeit products to be more advanced in technology, more professional in anti-counterfeiting performance, and more personalized. Therefore, the anti-counterfeit design is to consider the anti-counterfeiting characteristics of products in specific applications. Users use the changes in lines, patterns, lace, and characters to carry out anti-counterfeit designs on products in practical applications, so as to make the products more exquisite and safe.



(Author: School of Journalism and Communication, Wuhan University)

Reprinted from: "Guangdong printing" 2004 5 Author: Lu Ruiqi