Glossary

A hologram that can be seen by light passing through the material containing the holographic recording. Ironically, all metallised, embossed holograms are transmission holograms but are conveniently seen by reflected light because the incident light passes through the diffractive grating and is reflected back by the mirror coated on the reverse side.

The passing of light through an object (as opposed to light reflecting off or absorbed by an object). Watermarks in security paper are usually viewed in transmitted light by holding the paper up to the light source.

A transparent area on a banknote incorporating optical effects by applying different elements, such as inkless embossing, liquid crystals or an optically variable device. Currently used both on polymer and paper banknotes.

Anglo-Saxon weight unit, equivalent to 31.10 grammes. Used in the precious metals industry.

A person or legal entity providing and preserving digital certificates to create and validate electronic signatures and authenticate their signatories.The TSP has the responsibility to assure the integrity of electronic identification for signatories and services through strong mechanisms for authentication, electronic signatures and digital certificates.

While RFID is a generic term encompassing different operating radio frequencies and standards, UHF is a frequency band covering 300MHz to 3GHz. UHF systems are known for generating long read ranges, up to 12m, whereas high frequency (HF) systems carry a much shorter read range, of approximately 1m. UHF allows for a faster data transfer rate, up to 20 times the range and speed of HF systems.

A photochemical process in which high-intensity ultraviolet light is used to instantly cure or ‘dry’ inks, coatings or adhesives.

A first-level requirement of security paper, which needs to be made from virgin pulp without optical brighteners (ie. which is UV-dull). This is because optical brighteners mask or interfere with UV fluorescent security print and fibres.

Electromagnetic waves located beyond the blue end of the visible light spectrum, commonly defined within the wavelength range of 100nm-400nm. UV light is often used to analyse secure documents and banknotes, and security features such as paper brightness, fluorescent inks and fluorescent fibres. UV lamps used in shops and banks to verify banknotes operate at a wavelength of 365nm.

People who do not have a bank account.

A coin which has not been distributed or used as currency.

People who have a bank account but do not actively use it. For example, they may receive a government benefit payment into the account but they then withdraw it in cash and do not use the account further.

The opposite of a fit banknote. A banknote which, due to its deterioration or poor quality, is no longer suitable to be returned into circulation, and will be destroyed by the central bank.

A coin, banknote, medal or token which has only been struck on one side.

Colloquially termed ‘web address’. A reference to a web resource that specifies its location on a computer network and a mechanism for retrieving it.

In the context of product traceability, a unique identifier is a serial number, assigned by a central authority for application to unit packages of products for the purpose of track and trace. No two serial numbers are the same, thereby allowing for the identification of individual retail-saleable items throughout the supply chain.

The smallest individual packaging of a tobacco product (one pack of cigarettes usually holds 20 individual sticks).

Device designed to allow central bank digital currencies to be held and used offline. This could be a card or a specialised device.

The first, and most common 1D (linear) barcode for retail product labelling, encoding global trade item numbers (GTINs) in line with GS1 international standards. UPCs are composed of 12 digits encoded in a series of vertical lines. The first six digits correspond to the manufacturer’s identification number, the next five represent a specific product type and packaging configuration, and the last one is a check digit.

A material that absorbs energy at a longer wavelength outside the visible spectrum and emits in the visible spectrum. The materials that can achieve this effect are rare and therefore used for security marking.

A process for creating a layer of metal on a substrate. Involves heating the metal target material until it vapourises inside a vacuum chamber. This allows the metal vapour to condensate and form a thin layer over the top of the substrate. Vacuum deposition is a common method of producing security threads.

The use of digital print processes to apply personalised and serialised information, such as unique identifiers and barcodes, to products and documents.

Applied to a banknote, this is the process by which the surface of the note is coated with a layer of varnish with the purpose of decreasing the level of absorption of the substrate, thereby reducing its soiling and prolonging the life of the note in circulation.

Unlike raster images, a vector is not composed of separate dots (pixels). Vector graphics are composed of control points with curves in between them, defined by a mathematical formula. Vector graphics are often used for printing brochures etc., which do not require accurate transmission of all the shades of a particular colour and which can be described by curves. A great advantage of vector graphics is that the scaling of images does not affect their quality. One of the most popular vector graphics editors is Adobe Illustrator.

The process of verifying specific identity, document or product attributes, or determining the authenticity of credentials in order to give authorisation for a particular service.

A small illustration on a banknote that fades into the background rather than being framed by a border.

A technology that immerses the viewer in a computer-generated simulation of a 3D scene and allows them to interact with it using a digital interface. VR devices often use the term ‘hologram’ to describe the heightened sense of realism they provide.

A permission to enter the territory of a country. Can be in the form of a sticker with a multilevel security system, an insert, a stamp or a small sticker. A visa is placed on special pages of a travel document. There are machine-readable and non-machine-readable visas.

The reformation of cellulose to give a textile fibre that may carry security features and be embedded into security paper.

The fraudulent practice of making phone calls or leaving voice messages purporting to be from reputable companies in order to induce individuals to reveal personal information, such as bank details and credit card numbers.

A cryptographically signed data structure containing document features, encoded as a 2D barcode and printed on a document. The use of a VDS is recommended by ISO 22381:2018 as an open source, trusted entry point to allow all stakeholders to authenticate a unique identifier without having to go online, as well as access information on the security features used on a security document.

Wavelengths within the visible spectrum of 380nm-740nm.

Tamper-evident labels that reveal a covert ‘void’ message when removal of the labels is attempted. Also refers to anticopy labels that, upon scanning, reveal the word ‘void’ in the copy.

A method of making copy-evident and tamper-resistant patterns in the background of a document. Normally these are invisible to the naked eye, but become obvious when the document is photocopied. Typically, they spell out ‘void’, ‘copy’, or ‘invalid’. See also Big dot little dot.

Refers to holograms where the thickness of the recording material is much larger than the wavelength of light used for recording. One of the most common types of hologram (together with surface relief holograms), volume holograms are mass-produced through optical copying of a master hologram onto photopolymer materials, so they retain more of the optical properties of the master than the mechanical, surface relief process. This allows them to be used for classical holograms which are fully 3D images, displaying depth and both vertical and horizontal parallax. Volume holograms are either monochromatic or two-colour, with a distinctly different appearance to rainbow holograms, which are based on diffraction.

A means of defacing coins to render them worthless/unfit for circulation prior to being melted down or sold for scrap. The process takes its name from the pattern forced into the surface of coins under extreme pressure, which distorts it by creating a series of wavy lines similar to a waffle.

An image in paper produced by varying the thickness and density of the paper mass during paper production. These variations form a discernible image that can be viewed when holding the paper up to the light. Used as a security feature on most banknotes.

A type of marker directly embedded within video, audio or print content, which is imperceptible to humans but readable by computers.Typically used to identify ownership of copyright and authenticate a genuine article.

A part of the production process of many security papers that uses pressure through a wire mesh to form designs or patterns by varying the thickness of the paper.

A photonic watermark for banknotes, developed by combining a invisible photonic printing with a translucent and ultra-thin magnetic-responsive photonic display film.

A property of electromagnetic radiation that denotes the distance between waves of light.

A mathematical means for performing a signal analysis when signal frequency varies over time.

A category of electronic devices that can be worn as accessories, embedded in clothing, implanted in the user’s body, or even tattooed on the skin.

A continous roll of flexible material, usually paper, foil, film or laminate in a roll form.

Involves the feeding of a continuous roll (or web) of paper through the printing press. Web-fed offset lithography (as opposed to sheet-fed offset) is the predominant print process for tax stamps and other security labels.

The application of a coating of wet glue to a dry substrate before it is attached to an item. This is the main way of applying tax stamps to products.

An indirect lithographic printing process where a flat printing plate prints onto a rubber blanket that transfers the image onto the paper. The printing plate must be moistened with water before it is inked, with the water adhering to the non-image area.

The severe polishing of a coin in an attempt to improve its appearance and saleability to the uninformed.

World Health Organisation Framework Convention on Tobacco Control (WHO FCTC) global treaty, and its Protocol to Eliminate Illicit Trade in Tobacco Products. The Protocol requires all parties to implement secure track and trace systems by 2023.

A paper-embedded security thread surfacing at regular intervals in a document and full visible when viewed in transmission.