Optically variable ink (OVI) also called color shifting ink is an anti-

counterfeiting To counterfeit means to imitate something authentic, with the intent to steal, destroy, or replace the original, for use in illegal transactions, or otherwise to deceive individuals into believing that the fake is of equal or greater value tha ...

measure used on many major modern

banknote A banknote—also called a bill (North American English), paper money, or simply a note—is a type of negotiable instrument, negotiable promissory note, made by a bank or other licensed authority, payable to the bearer on demand. Banknotes w ...

s, as well as on other official documents ( professional licenses, for example). The ink displays two distinct colors depending on the angle the bill is viewed at. The United States fifty-dollar bill, for example, uses color shifting ink for the numeral 50 so that it displays copper at one angle and bright green in another. OVI is particularly useful as an anti-counterfeiting measure as it is not widely available, and it is used on

security printing Security printing is the field of the printing industry that deals with the printing of items such as banknotes, cheques, passports, tamper-evident labels, security tapes, product authentication, stock certificates, postage stamps and identit ...

. One major manufacturer is a

Swiss Swiss may refer to: * the adjectival form of Switzerland * Swiss people Places * Swiss, Missouri *Swiss, North Carolina * Swiss, West Virginia * Swiss, Wisconsin Other uses * Swiss-system tournament, in various games and sports *Swiss Internati ...

company called

SICPA SICPA (acronym for the former name ''Société Industrielle et Commerciale de Produits Alimentaires,'' no longer in use) is a Swiss company that provides security inks for currencies and sensitive documents, including identity documents, passp ...

(Société Industrielle et Commerciale de Produits pour l'Agriculture). Additional suppliers include German company

Gleitsmann Security Inks E.T. Gleitsmann was a German producer of printing ink, founded in Dresden in 1847 by Emil Theodor Gleitsmann. It would later expand into an international network with branches in Austria ( Vienna/Rabenstein), Hungary ( Budapest), Italy ( Turin) ...

Sun Chemical Sun Chemical is the world's largest producer of printing inks and pigments and is located in Parsippany-Troy Hills, New Jersey. It was incorporated in 1945. The company has its roots as the Lorilleux & Cie. Paris in 1818, but was incorporated ...

(through their Brand Protection Division based in Manchester, UK), and the Swiss company Printcolor AG, located in Berikon, Switzerland. Color-shifting inks reflect various wavelengths in white light differently, depending on the angle of incidence to the surface. An unaided eye will observe this effect as a change of color while the viewing angle is changed. A color copier or scanner can copy a document only at one fixed angle relative to the document's surface. It uses finely powdered

pearlescent Iridescence (also known as goniochromism) is the phenomenon of certain surfaces that appear to gradually change color as the angle of view or the angle of illumination changes. Examples of iridescence include soap bubbles, feathers, butterf ...

glitter Glitter is an assortment of small, reflective particles that come in a variety of shapes, sizes, and colors. Glitter particles reflect light at different angles, causing the surface to sparkle or shimmer. Glitter is similar to confetti, sparkle ...

Optically variable magnetic ink

Optically variable magnetic ink (OVMI), also called SPARK, has visual effects that are based on the magnetic properties of the ink. When the document is tilted, movement of a bright light stripe occurs and the colour changes. It is usually applied by screen printing. This type of ink is used for the

Euro The euro (symbol: €; code: EUR) is the official currency of 19 out of the member states of the European Union (EU). This group of states is known as the eurozone or, officially, the euro area, and includes about 340 million citizens . ...

Brazilian real The Brazilian real (pl. '; sign: R$; code: BRL) is the official currency of Brazil. It is subdivided into 100 centavos. The Central Bank of Brazil is the central bank and the issuing authority. The real replaced the cruzeiro real in 1994. A ...

, and

Russian ruble ''hum''; cv, тенкĕ ''tenke''; kv, шайт ''shayt''; Lak: къуруш ''k'urush''; Mari: теҥге ''tenge''; os, сом ''som''; tt-Cyrl, сум ''sum''; udm, манет ''manet''; sah, солкуобай ''solkuobay'' , name_ab ...

banknotes.

References

Money forgery {{money-stub