The important position of ink and paper in security printing

With the understanding of counterfeit products, people are increasingly aware of the important position of ink and paper in security printing. Discuss the roles of the two separately:
First, ink Many security inks can mark "the original has been changed" or prove that an original is true. The following is the introduction of some security inks:
1. Chemical solvent reaction inks These inks disappear, fade, and become dirty when in contact with wipes, bleach, water, or other solvents.
The ink that reacts with the solvent is usually printed in a background area or in an area of ​​the document. For example, when this ink is used to print the data area of ​​a check, changes in the check can be easily detected. Depending on the ink type, the ink will disappear, fade, and become dirty when changed. These inks can be used for many documents to prevent damage, one of its main applications is discount cheques.
Chemically sensitive inks are evaluated by the ANSI X9B10 committee. Their ability to prevent changes is strong. 3/10 of this capacity is to prevent erasure and 7/10 is to prevent reaction with bleach and other solvents.
2. Erasable inks Erasable inks provide a clearly visible indication that is often used to print background colors. If someone wants to change the check, the ink will be erased. A bright or light-colored solid background is most effective because erasing can be significant and the background is not easily copied by a color copying machine. Erasable inks come in a variety of colors, including fluorescent light. One of its applications is the hotel guest check, which includes the background of the area printed with erasable ink. If the customer tries to change the total by erasing, the colored background will disappear.
3. Fluorescent ink This ink, sometimes invisible to the naked eye, emits light under ultraviolet or infrared light, and due to its convertible and hidden features, the heart cannot be accurately reproduced on a color copying machine, making the ink in a certain These applications are becoming more and more popular. Some parts of the cheque, such as the MICR line, can be made fluorescent, or a whole block of the cheque is characterized by a fluorescent color. For example, the watermark is sometimes printed with fluorescent ink. Many currencies in the world are printed with fluorescent inks, which have a wide color range.
4. Infrared ink This ink absorbs or reflects infrared light. When a box of black infrared ink is printed on a message, the ink is used to cover the "true" or "original" information. This information can only be read under the infrared light. The information itself can also be printed with infrared ink and can only be displayed under infrared light. Just like using fluorescent inks, the person who verifies the document must have the knowledge of the ink presentation and the appropriate equipment.
5. Permeation ink Penetration ink is commonly used to print MICR data on cheques. The ink will penetrate the bottom layer and display the printed content on the back of the document. Digital changes and other illegal information can be detected by comparing the front and back sides. In some special cases, invisible fluorescent ink can be added as a cover feature to provide special security.
Penetration ink can be used on a cash register to prevent customers from changing information in order to obtain more money from the rebate, and the ink can also prevent copying of the record slip.
6. Thermal Chrome Ink This ink is also called thermal ink. When a person touches a document, the ink will change color due to the influence of the human body temperature, and when it is no longer touched, it will change back to the original color. The ink is now being used on medical prescriptions to reduce medical fraud. General thermal chromium ink is printed on one side of the table below the patient's name, age, address, and date. The ink will automatically disappear when touched.
There are many kinds of color transformations, from blue to colorless, orange to yellow to red to colorless. The dual thermal chromium ink will discolor it when rubbed, and the friction will make it continue to change to another different color. The colorless to non-ferrous conversion of the thermal chromium ink is mainly used for direct mailing, advertising, promotional materials, packaging, labels, education and learning aids, stationery and other novelties; color to colorless thermal chromium ink is mainly used For security documents, because even a color blind can identify colored to colorless transitions and test documents.
Many suppliers offer friction-stained inks that change color due to friction rather than body temperature. Just like with a carbon-free coating, the ink is packaged and coated and the inspector is required to scrape it with a fingernail or object to discover the information. Unlike thermal chrome inks, this ink does not change back to its original color. It also undergoes chemical changes, and the ink automatically turns blue or partially blue when in contact with chemicals. This ink is used for documents, important cheques, and can be printed publicly or implicitly.
Second, paper security paper is a rapid growth in the paper industry, it can effectively prevent documents from being tampered with. There are many companies in the United States that are beginning to provide security paper. Many of the technologies discussed below (not exactly) are provided by several paper manufacturers.
1. Chemical reaction paper This paper reacts with the following solvents: bleach, nail rust remover, gasoline, kerosene, paint thinner, and turpentine. When reacting with a solvent, the paper turns to another color or shows a multi-symbol of useless information.
2. Safety Fibers and Marking Materials Paper manufacturers supply a variety of raw materials for the production of safety paper, such as hidden or open fibers, marking materials, and the like. Impressive materials such as fluorescent fibers or marking materials can all be detected with UV light. Like fluorescent security inks, fluorescent fibers and marking materials cannot be copied or scanned.
3. Toner Curing Paper This type of paper is considered to be easier to "adsorb" laser printing toner than plain paper. This feature makes it difficult for criminals to change checks or other information. This point is designed for end users who use lasers to print checks.
4. UV dull/dead paper (dull: partially transmitted light or reflected light; dead: opaque or non-reflective light)
UV dull paper extracts most of the fluorescent colors from the paper, whereas UV dead paper does not have a fluorescent color at all. Watermarks printed on fluorescent UV inks on UV dull/dead paper will be brighter under UV light because paper does not affect the watermark.
5. Watermarks There are many types of watermarks for secure documents, such as web watermarks. When the paper is wet, an image is imprinted on the paper, and when facing the light, the watermark can be seen from both sides of the document.
Artificial watermarks can also appear on both sides. Sometimes it looks like a real watermark. It's just cheaper than a real watermark because it doesn't include the cost of molding. Both watermarks are hard to duplicate. Watermarks can be printed with fluorescent inks, so they emit light under ultraviolet light.
Third, the key to the successful use of the security features of the future security printing lies in the level of knowledge and correct use of document inspectors. For some suppliers, how to teach end users and document inspectors to detect the security features based on ink and paper is a big problem. Some suppliers rely on manufacturers to teach customers, or ask manufacturers to hold workshops for their customers.
But whether it is a machine inspection or a manual inspection, neutralizing inks and papers generally have better safety features than relying solely on ink or paper. The more security features a document contains, the less easily it can be forged.