Traditional seals mainly consider engraving and use, so they do not have anti-counterfeiting features. From personal handprints to corporate seals, from the seals retained by banks to the printing of certificates issued by public security agencies, these are basically methods of letterpress engraving and red ink. How long has this method been used? For fear that only historians will know. The traditional seal uses the letterpress mode, which is to engrave by hand or machine, so that the lines of the word are preserved, and the blank part is hollowed out. Its character is on a plane. The effect of this engraving is to make the imprints smooth, with no relief, only to show The size and shape of the word, the thickness of the line. Although the traditional seal can be used arbitrarily, there is only a difference in color among various inks, and there is no obvious difference in other effects, making it extremely easy to be imitated. At present, the use of computer engraving technology makes it easier to imitate such a seal imprint. Because the fonts in the computer's own font are limited, the size of the word also has limited changes. When a copy of a seal is to be imprinted, the required font size and size will soon be available in a limited font. Because the lettering accuracy is also high, It's easy to get realistic imitations.
Gravure seal has a certain anti-counterfeiting capabilities. Gravure printing has a long history. Due to its good anti-counterfeiting effect, it has been widely used in more important printing such as bills, renminbi, and stamps. There is a big difference between gravure printing and letterpress, mainly in the aspects of plate making and printing ink. The gravure plate engraving method uses the line hollowing method to trace the text and pattern to be printed on a plane, and then manually or mechanically sculpts the text or the pattern part, leaving the blank part still on the original plane. When printing, the special ink is filled with hollowed-out fonts, the excess ink on the blank surface is erased, and the template filled with the ink is imprinted on the substrate, leaving a corresponding text or pattern on the substrate. From the point of view of the shape and size of printed text, there is no difference with the effect of letterpress printing, but when you touch and compare with your hand, you will find that there is a big difference: the letterpress printing is relatively smooth, with a smooth feeling, and gravure printing There is a clear sense of convexity and concaveness, as if the text was sculptured. This is one of the anti-counterfeiting features of gravure printing. If during the gravure process, the pit of a certain word is intentionally carved deeper, then the pit will accommodate more ink, so that when transferred to the substrate, more ink deposits form a convex sense. In the same way, if the pit of a word is shallow, a concave feeling will be formed. This convex and concave feeling is difficult to achieve in relief printing. If we change the traditional letterpress seal to the gravure seal, we believe we can also achieve better security.
The so-called gravure seal is to make the corresponding gravure seal according to the gravure plate making and printing characteristics, and it is also used according to the gravure printing principle. There are two main differences between the seal and the common seal. One is that there are differences in the platemaking, that is, the text on the seal is hollowed out, rather than the blank is hollowed out; the second is the difference in use, that is, filling in the pits of the seal. The ink is printed, and then the ink in the blank part of the text is erased, and then contact printing is performed. Obviously, gravure imprints are more complex than letterpress imprints in terms of platemaking and use. This may be the main reason why they are not used. However, on the other hand, it is because of differences in platemaking and use that it is possible to provide security for imprints.
Use hand-engraving to improve the anti-counterfeiting features of gravure seals. Gravure seal engraving is equivalent to gravure plate making. There are many kinds of gravure plate making methods, such as hand-engraving plate engraving, mechanical engraving plate engraving, electronic engraving plate engraving, computer-controlled engraving plate engraving and so on. Although these platemaking methods can all be used for gravure seal platemaking, the manual engraving of plates is the best method from the aspect of seal security. The advantages of hand-engraving platemaking mainly include two aspects. First, the resolution of the engraving is higher. Second, the depth of text pits can be actively controlled during engraving. Both of these aspects have a direct impact on the effectiveness of anti-counterfeiting.
Each sculptor has his own style of sculpting, or shows his differences with other people through exquisite tactics or elegant words. In order to prevent falsification, the seal of the seal is delicate, which makes it possible to achieve a very high resolution in the processing of some texts. There are clear traces of where the blade strikes. Whether through mechanical plate or through the efforts of other hand-carvers, these traces are Hard to imitate.
Reasonable use of ink improves the anti-counterfeit function of the gravure seal. The pits of the intaglio seal are relatively deep, so they have better adaptability to the larger ink particles. This is actually broadening the selection range of the ink, so that we can freely choose special inks such as magnetic ink, thermal ink and photosensitive ink.
Select magnetic ink printing, when these words contact with a specific magnetic field, it will cause a corresponding response, or sound alarm or light alarm, so as to distinguish between true seal and fake seal. In order to increase the strength of anti-counterfeiting and avoid illegal imitation of magnetic seals, you can choose different types of magnetic inks (mainly differences in magnetic strength), and change over time, such as single or double daily replacement or annual replacement and many more. What kind of use, what type of use, should have someone to manage, record. Because different types of ink reflect the magnetic field is not the same, so as not to distinguish themselves. This method requires a special set of testing equipment, so the implementation of the relatively high cost, it is more suitable for the use of banks and other special industries in the anti-counterfeiting of the seal, due to the implementation of the cost is relatively large, so the effect of anti-counterfeiting may be better.
Thermal inks add a heat-sensitive material to the ink. When a heat-sensitive ink is used for the seal, the heat-sensitive material is transferred along with the ink to the corresponding stamp carrier. Heating the graphic part of the seal mark will cause partial discoloration of the graphic and text. As the temperature changes, the color of the seal will change accordingly. There are many kinds of temperature-sensitive inks. Selecting different temperature-sensitive inks will show different colors in different temperature ranges. The combination of different colors in various temperature segments will form the corresponding secret, which is generally difficult to imitate, thus increasing the security of the seal.
Photosensitive ink is a kind of light-sensitive material added in the ink. The method of adding photosensitive ink is basically the same as that of the heat-sensitive ink. However, under different light intensities, the seal marks show different colors. In practical use, a variety of sensitive materials can be used in combination to make the seal traces reflect light, heat, magnetism, etc., and adopt different proportions, which reflect the content is not the same, will receive better The anti-counterfeiting effect. Because the temperature-sensitive ink and the photosensitive ink have the characteristics of being convenient to use, no special equipment is required, so it is easy to use for security of public seals. Using the invisible seal method will have a better anti-counterfeiting effect. There are many methods for anti-counterfeiting seals, and invisible methods can also be used. The so-called invisible, in fact, is a method of covering, that is, the ink containing special components covered with black or other colors, the surface is a geometric pattern, is actually a covered seal, only under certain conditions can reveal its seal content . There are many types of specialty inks, such as magnetic inks, photosensitive inks, and so on. Due to the influence of traditional concepts, this method is only suitable for informal occasions. It does not apply to formal diplomas, introduction letters, etc.
The gravure seal uses ink anti-counterfeiting, and its technology is directly proportional to the anti-counterfeiting effect. That is, the more complex the technology, the better the anti-counterfeiting effect. Taking photosensitive inks and temperature-sensitive inks as examples, the temperature of thermal discoloration can be controlled within a narrow range, such as about 80°C, through different formulations so that when we are in general contact, there will be no discoloration. When the temperature is increased to about 80°C, color changes will occur and the seal will be determined to be true. If discoloration occurs at a lower temperature, the seal is a copy. In actual production, two or more methods of temperature change can be used, and the anti-counterfeiting effect will be better. That is, the combination of heat-sensitive materials is properly selected so that the imprint traces show different colors at different temperatures, and the imitation is more difficult.
The use of thermal inks or photosensitive inks combined will have better anti-counterfeiting effects. A single photosensitive or thermal ink technology may still have the problem of simple technology and easy to imitate. At this time, a composite ink of both can be used, and the anti-counterfeiting effect will be better. The method is to mix the two according to a certain proportion (formula confidentiality). The specific stamping operation is the same as other stamps. The difference lies in the identification and identification. Since it is a composite ink, it is necessary to have both light and heat conditions to reveal the seal. Different ink ratios require different light intensity and temperature. If you avoid the normal temperature and the common light, you must use the instrument to achieve it. This will increase the difficulty of seal recognition and increase the security effect accordingly.
Compared with ordinary seals, the gravure seals are more complicated to use, inconvenient to carry, and the identification is more troublesome. People are still difficult to accept in a short period of time. However, it is its complexity that brings about an ideal anti-counterfeiting effect. In view of this, it is suggested that the anti-counterfeiting of seals be used in the graduation certificate of colleges and universities firstly, accumulate experience, and then introduce other fields. This may be a more prudent approach. If you can refer to expert opinions when making and using intaglio seals, you will receive better anti-counterfeit effects. Anti-counterfeit gravure seal must pay attention to two points in the production and use, the first is to use a special production method, it is best to use hand-carved, try not to use computer engraving, and second, the ink used in gravure seals to be prepared under the guidance of experts, Easy to form secret anti-counterfeiting. (Wu Longqi) (From "China Packaging News") (From "China Packaging News")
Fake diplomas, fake documents, fake invoices and other markets are obvious to all. These illegal activities characterized by counterfeit seals were able to spread in a very short period of time. On the one hand, they explained that the relevant departments did not exert sufficient efforts to combat them. On the other hand, they also stated that the owners of the seals had weak anti-counterfeit awareness. Giving criminals opportunities to make it easy to fake. To eliminate the harm and adverse impact that such bad behavior has brought to society, it is necessary not only to crack down on the relevant departments, but also to require the owner of the seal to improve their awareness of prevention, increase the strength of anti-counterfeiting of seals, and increase the difficulty of imitation of seals. Your social rights are effectively protected. This article puts forward some corresponding measures on the anti-counterfeiting aspects of seal printing, and hopes to achieve the results.