Security printing
When security features of banknotes defined security features are referred to, which are incorporated into banknotes, so that they can be distinguished from counterfeits. By introducing a lot of these spoofing is much more difficult or even impossible.
Euro banknotes have an estimated 50 different types of security features. These are divided into safety features that are recognizable by people and machine-readable features. For historical reasons, have old banknotes on humanly recognizable security features. Only a subset of all features is publicly known; Moreover, only a part of the features of the issuing central or central banks will be described, and so exposed to the public evaluation.
From people recognizable features
Many safety features aim to be directly detected and evaluated by people. These features can be usually not evaluate automated, so do not be machine-readable. In order to distinguish counterfeits from genuine banknotes, the knowledge about the basic look of a genuine bill is first necessary. In the note, there are a variety of features. Modern banknotes such as the euro or the Swiss franc have optical, haptic and acoustic security features. The European Central Bank advises for the test to procedure Feel - Watch - Tilt: First, the tactility of the bill should be checked, then the optical design and ultimately the behavior of certain optical characteristics of a tilting (opposite the incident light).
Counterfeiters fake from an economic point of often only individual characteristics, sufficiently well and neglect the rest. A multi-phase approach - as described above - significantly reduces the likelihood of obtaining counterfeit money.
Haptic security features
Bills are largely from a cotton -based substrate (substrate ) was prepared. Since the end of the twentieth century increasingly banknotes are issued, the polymer-based - are created - so plastic. Polymer notes have the advantage that they are water resistant and thus better suited for humid regions of the world. The disadvantage is that polymers reduce the hurdle for counterfeiters and that another " paper feel" is.
Optical security features
Optical safety features are probably the most obvious security features of a banknote. The awareness that bills contain watermarks that are easy to see against the light, or that security strips are incorporated into the paper, is widely used. But in addition to the visible by day, there are other security features that are revealed only under specific conditions.
Back of a 50 - euro banknote under white ( day) light
An anti-copy grid
An anti-copy - grid is a very fine resolution raster image. If too low, scan- resolution, as is the case with copying machines, the fine grid elements can not be completely reproduced. This lost picture elements, partly arise even noticeable moiré pattern.
Through window
In bank notes, the use as the substrate polymer, it is possible to incorporate a see-through window. This safety feature is, for example, in the Bulgarian 20 - Lev's note, the Australian dollar notes, the Romanian leu, the recent Chilean 2000 -peso note, the Mexican 20 - used and 50 -peso notes and the Singapore dollar bills.
Through register
From a see-through register (Review Passer ) is when a complementary pattern is printed split between the front and back of the bill. Examples are the Swiss cross, the D the last D- Mark banknotes or the value numeral on the euro. A see-through register completes itself against the light, since then complete both sides exactly. Through register are very difficult to reproduce because the highest accuracy is required for duplex printing.
Through register on a 5- Deutsche Mark banknotes ( BBk III) ( back)
Through register on a 5- Deutsche Mark banknotes ( BBk III) (Review)
Through register on a 100 EUR banknote ( front)
Through register on a 100 EUR banknote ( back)
Through register on a 100 EUR banknote (Review)
Through register on a 25 - guilder banknote (Review)
Through register on a 1,000 escudo banknote (Review)
Through register on a 50 -franc banknote (Review)
Color pairs
By using the metamerism ( color pairs ) are visually similar color schemes printed, meeting in the CMYK color space of the same place, but result from the application of optical test equipment (such as in the IR region ) different results.
Infrared light ( IR filter: 700 nm) of the back of a 50 - euro banknote. The serial number faded bottom left, not top right.
Infrared light ( IR filter: 1000 nm ) of the front of a 50 - euro banknote. Most colors have disappeared (the European flag at the top left), so you can see the paper structure well. The watermark (left) are clearly visible.
Infrared light ( IR filter: 1000 nm) of the back of a 50 - euro banknote. Up to 50 lower right and the serial number right above all the colors are gone. The watermark can be easily recognized.
Fluorescent colors
It is used ink containing fluorescent pigments. Irradiation of the bill with short-wavelength UV light, so different colors are emitted in the visible light spectrum depending on the pigment choice. Which areas reflect in color which is dependent on the wavelength of the UV light source.
Excitation with UV light ( 350 nm) of the back of a 50 - euro banknote. Again, the security fibers are easily visible
Excitation with UV light ( 250 nm ) of the front of a 50 - euro banknote. The film of kinegram bottom right is off. But the stars of the European flag and the EURion circles stand out in red.
Excitation with UV light ( 250 nm) of the back of a 50 - euro banknote.
Film elements
Through the input and application of an optical film elements and difficult reproducible surface marker is reached. Kinegrams or holograms are produced by printing patterns that are incorporated as Metall-/Kunststofffolien. They represent a viewing angle dependent appearance that show two - and three-dimensional figures or movements.
Kinegramm on a 100 -DM banknote ( BBk IIIa)
Kinegramm on a 200 -DM banknote ( BBk IIIa)
Film element ( hologram ) on a 50 EUR banknote
Film element ( hologram ) on a 100 EUR banknote
Gloss effects
The setting of individual highlights ( elements react in direct lighting) requires a special printing technique. It behaves similar to the optically variable ink.
Gloss effect on a 5- euro banknote ( Gold)
Guilloche
As Guilloche refers curving pattern, as they are also found on many passports. They consist of superimposed printed in different colors and wave loop patterns.
Iris print
When Iris print a color gradient of the ground color of the banknotes is produced by appropriate printing machines. This is difficult to reproduce by color copier in the exact course.
Colored fibers
The paper can be mixed colored fibers; with a corresponding coloring can colored fibers under ultraviolet light glow in different colors (see gallery)
Micro - perforation
Micro - perforation for example, there on the Swiss franc, the Romanian lei and the euro. It be punched, for example, in the substrate or in a film element pinholes, without a " craters " formed. Against the light, the holes usually form a pattern, eg a score of the Swiss franc or the euro symbol in the banknotes from 50 € in Kinegramm.
The small holes in the bill provide the number 20 (CHF )
Microscript
On many bills to letterings are in micro-printing, thus the smallest font. With the naked eye, these writings are difficult to detect. In the euro banknotes they are incorporated as picture elements in the motifs. With a magnifying glass micro text can be read. Micro prints can be produced with special CTP for steel engraving or offset printing machines. The image resolution of commercially available imagesetter or even of inkjet printers is too low for reproduction. The micro-printing on the front D- Mark banknotes ( BBk-III/IIIa ) is just ¼ mm high.
- Magnification of microscripts
100 Euro banknote ( front, bottom left)
100 Euro banknote ( front, near the large figure of merit )
20 - Swiss -franc banknote ( front)
100 - yuan banknote ( back)
1,000 -peseta banknote ( front)
Optically variable ink
In the optically variable ink (English optically variable ink, abbreviation POI), the perceived color changes depending on the viewing angle by which light is refracted to the pigments, scattered or reflected. This safety feature is, inter alia, used in the four biggest euro bank notes on the back. There, the value number changed from purple to olive brown white box. Even in the last series of the D- Mark, the lower part of the great value number on the front of the 500 and 1000 mark notes with optically variable ink was printed.
Register printing
Different patterns or symbols will be printed at the register printing on or to each other that they together form a recognizable image. The slightest deviation by registration inaccuracies can be detected with the naked eye, because the image will be distorted. It is especially difficult to achieve the high accuracy level when the partial images on two different sides of the bill are ( through register ) is.
Scrambled indicia
As Scrambled Indicia is called micro-printing patterns that can only be seen by means of a decoding lens as an image.
Security thread
The security thread is normally a 1-2 mm wide metallized strip within the paper, since it is already incorporated into the paper pulp. An improvement is achieved in that it is partially open as window security thread, by being drawn into the bulk and on the surface. In addition, it may additionally be provided with a print or with other optical or invisible characteristics. The currently most prominent security thread motion was first used in 2006 on the 1,000 -krone banknote Bank of Sweden. Using lenticular technology, a three-dimensional motion effect is created here. Security threads may not play typographical or forgery by photocopy.
Security thread on a 20 DM banknote ( BBk III) ( The thread comes in part from the paper )
Security thread on a 20 DM banknote ( BBk III) (Review)
( Only visible in the phantom) security thread on a 100 - euro banknote
Special colors
For printing spot colors are used in some areas that lie outside the color gamut of a CMYK printer, and thus can not be accurately reproduced faithfully by this. More color levels are outside of the RGB color space and are thus not correctly detected by a scanner.
Watermark
Watermarks may be incorporated in the paper of the banknote. They are usually found on the unprinted areas and can best be seen against the light.
Watermark on a 100 -DM banknote ( BBk IIIa)
Queen Elizabeth II as a watermark on a £ 5 banknote
Watermark on a 100 - euro banknote
Watermark on a 100 yuan banknote (including through register and OVI )
Substratum
Banknotes are printed on a special substrate; for banknotes it is called in this case from the substrate. Historically, it involves special paper, which is mainly made on the basis of seed fibers ( linters ) of cotton. Substrates made of cotton have the advantages that they are not destroyed by accidental washings and have a special " paper feel". For euro banknotes, a special cotton paper is used, the long fiber and resistant than normal paper. The exact composition of the paper is secret, and it is sold exclusively to central bank printing.
An alternative to cotton paper are polymer -based substrates. Such plastic banknotes show in some respects a better wear behavior than cotton -based notes. The disadvantage is that polymer banknotes are sensitive to heat and the production is more expensive. In addition, the uniqueness of the paper feeling as a security feature is lost. Polymer bank notes are in Europe only in Romania in circulation. Some other issues were from the Isle of Man and Northern Ireland by the Northern Bank. Outside Europe, polymer notes are to be found mainly in tropical and subtropical countries.
With special test pins quickly starch in the paper can be found. While originals are not discolor barely up, fakes are black immediately. This is not very safe method - on newsprint is no color change takes place - is often used due to cost and time constraints at retail.
One of the leading manufacturers of banknote and security paper is the paper Louisenthal, a subsidiary of Giesecke & Devrient, with production facilities in Gmund am Tegernsee and Königstein ( Saxon Switzerland ).
Acoustic safety feature
The sound of banknote paper at the " crumpling " or rubbing is influenced by a suitable paper fiber composition in bulk or by the coatings to the accompanying sound of writing or printing paper; Notes sound "harder". This does not apply banknotes on polymer-based ( plastic bank notes).