Security printing
More recently many of the techniques used to protect these high-value documents have become more available to commercial printers, whether they are using the more traditional offset and flexographic presses or the newer digital platforms.
Businesses are protecting their lesser-value documents such as transcripts, coupons and prescription pads by incorporating some of the features listed below to ensure that they cannot be forged or that alteration of the data cannot occur undetected.
In general, the introduction of a new banknote series is accompanied by information campaigns describing the design and the security features.
Several central banks also provide mobile apps explaining the characteristics by interactive methods and enrich them by animated effects.
Paper substrate may also include windows based on laser-cut holes covered by a security foil with holographic elements.
Some countries, including Canada, Nigeria, Romania, Mexico, Hong Kong, New Zealand, Israel, Singapore, Malaysia, United Kingdom, and Australia, produce polymer (plastic) banknotes, to improve longevity and to make counterfeiting more difficult.
A watermark is made by impressing a water coated metal stamp or dandy roll onto the paper during manufacturing.
A Diffractive Optical Element (DOE) within the transparent window can create a comparable effect but requires a laser beam for its verification.
Polymer banknotes which are printed on a basically transparent substrate easily provide clear areas by sparing the white coating.
The European Central Bank (ECB) recommends to look at the banknote against the light – the window in the hologram becomes transparent and reveals a portrait of Europa on both sides of the note.
Generally, pigments should be used at high concentrations to ensure that sufficient magnetizable material is applied even in thin offset coats.
A hologram may be embedded either via hot-stamping foil, wherein an extremely thin layer of only a few micrometers of depth is bonded into the paper or a plastic substrate by means of a hot-melt adhesive (called a size coat) and heat from a metal die, or it may be directly embossed as holographic paper, or onto the laminate of a card itself.
On occasion, the banknote designers succumb to the Titanic effect (excess belief in the latest technology), and place too much faith in some particular trick.
A frequent example of prismatic colouring is on checks where it is combined with other techniques such as the void pantograph to increase the difficulty of successful counterfeiting.
The advantage of a digital press is that in a single pass through the printer a void pantograph with all the variable data can be printed on plain paper.
The quality of the void pantograph is usually quite good because it was produced on a press with a very high resolution, and, when only a small number of originals are to be printed, it can be a cost-effective solution; however, the advent of the digital printer has rapidly eroded this benefit.
However, they are barely useful as a security feature because duplicates of an existing serial number are not easily detectable, except for a series of identical counterfeits.
In banknote printing the unique serial number provides effective means for the monitoring and verification of the production volume.
As an example, the euro series ES2 has different pattern of lines at the short edges of the banknote to support blind people in distinguishing the denominations.
For example, the value of a coupon might be encoded as a Halo image that could be verified at the time of redemption or similarly the seat number on a sporting event ticket.
Usually a marker turns newsprint black and leaves currency or specially treated areas on a document clear or gold.
In more advanced applications the marker creates a barcode which can be scanned for verification or reference to other data within the document resulting in a higher degree of assurance of authenticity.
This feature is also incorporated into many banknotes and other documents - e.g. Northern Ireland NHS prescriptions show a picture of local '8th wonder' the Giant's Causeway in UV light.
There are the following machine-readable features (extract): Because of the speed with which they can be read by computer systems, magnetic ink character recognition is used extensively in banking, primarily for personal checks.
The pigment is dispersed in a binder system (resin, solvent) or a wax compound and applied either by pressing or by hot melt to a carrier film (usually polyethylene).
[16] Some people believe that the magnetic ink was intended as a fraud prevention concept, yet the original intent was to have a non-optical technology so that writing on the cheque, like signatures, would not interfere with reading.
In the late twentieth century advances in computer and photocopy technology made it possible for people without sophisticated training to easily copy currency.
With the advent of Radio Frequency Identification (RFID) which is based on smart card technology, it is possible to insert extremely small RF-active devices into the printed product to enhance document security.
Biometric passports additionally include data for the verification of an individual's fingerprint or face recognition at automated border control gates.
[18] Most central banks also implement so-called Level 3 (L3) security features which are kept totally secret for their ingredients as well as their sophisticated measurement.
