Billions of dollars are spent annually to combat the crime of counterfeiting. With the advent of color laser printing, creating counterfeit documents became a major security concern. The printing industry has the challenging task of creating counterfeit-proof methods for checks, passports, currency, and other financial documents. An entire print market segment is dedicated to the science of security printing methods.

As new methods are developed to protect the currency and other important financial and federal documents, the counterfeit market continues to crack the code. Over the years, several methods have been employed with increasing success to make counterfeit documents more difficult to create. These methods have tested the boundaries of printing and finishing equipment. Determining which method to use to secure a document comes down to ascertain the likelihood of the item being counterfeited, as well as the exposure to loss if the document is falsely created.

With new methods being developed daily, it is impossible to list all of them; however, here is a summary of the 20 most common methods utilized in document security.

1. Special papers – Heavier stock papers are utilized for check printing.
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2. Watermarks – A watermark is an identifying image or pattern on paper that appears as various shades of lightness/darkness. Watermarks have been used on currency and other important documents.
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3. Intaglio printing – This is a technique that offers security printing solutions in which the image is incised into a surface and the incised line or sunken area holds the ink.
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4. Geometric lathe work – A geometric lathe is used for making ornamental patterns on the plates used in printing banknotes.
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5. Micro-printing – The usage of micro-printing in currency commonly exhibits the highest quality because it demands the highest level of counterfeiting deterrence.
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6. Optical variable ink – This ink displays two distinct colors depending on the angle at which the bill is viewed. It is used on many modern banknotes.
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7. Holograms – One of the most high-security printing methods is a hologram, an image made from a photographic technique that records the light scattered from an object and then presents it in a way that appears three-dimensional.
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8. Security thread – This consists of a thin ribbon that is threaded through the note’s paper. A security thread is a feature of many banknotes.
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9. Magnetic ink – MICR code is a character-recognition technology used by the banking industry to ease the processing and clearance of checks and other documents.
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10. Serial numbers – Serial numbers help make legitimate documents easier to track and audit.
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11. Copy-evident – Copy-evident technologies provide security to hard copy documents by helping distinguish between the original document and the copy.
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12. Prismatic coloration – This technique uses two or more colors in the background and blends them to create a prismatic effect.
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13. Halo – This uses two or more colors in the background and blends them to create a prismatic effect.
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14. Anti-copy marks – Anti-copying marks are the marks or designs on the piece of paper, that are used to create checks and banknotes. Some security printing software also helps in printing an anti-copy pattern.
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15. Fluorescent dyes – These show up as words, patterns, or pictures and may be visible or invisible under normal lighting. This feature is also incorporated into many banknotes and other documents.
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16. Registration features – This allows the note to be examined for this feature and provides opportunities to unambiguously align other features of the note to the printing. Again, this is difficult to imitate accurately enough in most print shops.
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17. Electronic devices – With the advent of RFID, it is possible to insert extremely small RF-active devices into the printed product to enhance document security. This is most apparent in modern biometric passports, where an RFID chip mirrors the printed information.
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18. Thermochromic ink – This is a security ink with a normal “trigger” temperature of 88° F (31° C), which will either disappear or change colors when the ink is rubbed, usually by the fingertips.
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19. False positive testing – The most common example is the widely available counterfeit detector marker seen in many banks and stores. Banknotes, being a specially treated substrate, usually behave differently than standard newsprint or other paper and this difference is how counterfeits are detected by the markers. Many consider it one of the best security printing methods.
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20. Latent images – Pressure-sensitive or hot stamped labels characterized with a normal (gray or colored) appearance. When viewed via a special filter (such as a polarizer) an additional, normally latent image appears.