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Security Paper
Security paper is a paper used in security printing that incorporates features that can be used to identify or authenticate a document as original, e.g., watermarks or invisible fibres in paper, or features that demonstrate tamper evidence when fraud is attempted, e.g., to remove or alter print such as amounts or signatures on a cheque. Examples of this kind of papers are used for banknotes and used for identification such as passports and certificates, such as birth certificates and different types of academic and qualification certificates, as well as government documents, e.g., voting ballots and tax strips. This also extends to personal and business checks, stock certificates, certificates issued by financial institutions and sensitive government-issued documents. The main use of security paper is to stop people from counterfeiting. History An initial patent for the manufacturing process for security paper was granted to Robert E. Menzies and John E. Aitken in the early 20 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Void Pantograph
In security printing, void pantograph refers to a method of making copy-evident and tamper-resistant patterns in the background of a document. Normally these are invisible to the eye, but become obvious when the document is photocopied. Typically they spell out "void", "copy", "invalid" or some other indicator message. Void pantographs work by exploiting the limitations and features of copying equipment. A scanner or photocopier will act as a low-pass filter on the original image, blurring edges slightly. It will also not be perfectly aligned with the directions of the document, causing aliasing. Features smaller than the resolution will also not be reproduced. In addition, human vision is sensitive to luminance contrast ratio The contrast ratio (CR) is a property of a display system, defined as the ratio of the luminance of the brightest shade (white) to that of the darkest shade (black) that the system is capable of producing. A high contrast ratio is a desired aspec .... This ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phosphorescent
Phosphorescence is a type of photoluminescence related to fluorescence. When exposed to light (radiation) of a shorter wavelength, a phosphorescent substance will glow, absorbing the light and reemitting it at a longer wavelength. Unlike fluorescence, a phosphorescent material does not immediately reemit the radiation it absorbs. Instead, a phosphorescent material absorbs some of the radiation energy and reemits it for a much longer time after the radiation source is removed. In a general sense, there is no distinct boundary between the emission times of fluorescence and phosphorescence (i.e.: if a substance glows under a black light it is generally considered fluorescent, and if it glows in the dark it is often simply called phosphorescent). In a modern, scientific sense, the phenomena can usually be classified by the three different mechanisms that produce the light, and the typical timescales during which those mechanisms emit light. Whereas fluorescent materials stop emitti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metallizing
Metallizing is the general name for the technique of coating metal on the surface of objects. Metallic coatings may be decorative, protective or functional. Techniques for metallization started as early as mirror making. In 1835, Justus von Liebig discovered the process of coating a glass surface with metallic silver, making the glass mirror one of the earliest items being metallized. Plating other non-metallic objects grew rapidly with introduction of ABS plastic. Because a non-metallic object tends to be a poor electrical conductor, the object's surface must be made conductive before plating can be performed. The plastic part is first etched chemically by a suitable process, such as dipping in a hot chromic acid-sulfuric acid mixture. The etched surface is sensitised and activated by first dipping in tin(II) chloride solution, then palladium chloride solution. The processed surface is then coated with electroless copper or nickel before further plating. This process gives u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holography
Holography is a technique that enables a wavefront to be recorded and later re-constructed. Holography is best known as a method of generating real three-dimensional images, but it also has a wide range of other applications. In principle, it is possible to make a hologram for any type of wave. A hologram is made by superimposing a second wavefront (normally called the reference beam) on the wavefront of interest, thereby generating an interference pattern which is recorded on a physical medium. When only the second wavefront illuminates the interference pattern, it is diffracted to recreate the original wavefront. Holograms can also be computer-generated by modelling the two wavefronts and adding them together digitally. The resulting digital image is then printed onto a suitable mask or film and illuminated by a suitable source to reconstruct the wavefront of interest. Overview and history The Hungarian- British physicist Dennis Gabor (in Hungarian: ''Gábor Déne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paper Money
A banknote—also called a bill (North American English), paper money, or simply a note—is a type of negotiable promissory note, made by a bank or other licensed authority, payable to the bearer on demand. Banknotes were originally issued by commercial banks, which were legally required to redeem the notes for legal tender (usually gold or silver coin) when presented to the chief cashier of the originating bank. These commercial banknotes only traded at face value in the market served by the issuing bank. Commercial banknotes have primarily been replaced by national banknotes issued by central banks or monetary authorities. National banknotes are often – but not always – legal tender, meaning that courts of law are required to recognize them as satisfactory payment of money debts. Historically, banks sought to ensure that they could always pay customers in coins when they presented banknotes for payment. This practice of "backing" notes with something of substance is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taggant
A taggant is any chemical or physical marker added to materials to allow various forms of testing. Physical taggants can take many different forms but are typically microscopic in size, included at low levels, and simple to detect. They can be utilized to differentiate authentic product from counterfeits, provide identifying information for traceability purposes (e.g. lot number, company name), determine mixing homogeneity and cross-contamination, and to detect dilution of proprietary products. Taggants are known to be widely used in the animal feed industry, plastics, inks, sheet and flexible explosives, and pharmaceuticals. An RF taggant is a radio frequency microchip used in automated identification and data capture (see RFID). In such cases, electronic devices use radio waves to track and identify items, such as pharmaceutical products, by assigning individual serial numbers to the containers holding each product. This technology may prevent the diversion or counterfeiting ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ink Eraser
An ink eraser is an instrument used to scrape away or chemically bleach ink from a writing surface. This is a more involved process than removing pencil markings. Pencil marks can be gradually adhered to natural rubber fragments by rubbing the mark with a pencil eraser (this action is what prompted Joseph Priestly to give solidified latex its common name.) Ink, however readily penetrates the fibers of most papers and is therefore more difficult to extract by mechanical action. Older ink erasers are therefore small knives designed to scrape off the top few microns of a sheet of paper, removing the ink that had penetrated. In concert with bladed ink erasers an eraser similar to those at the end of pencils was also used, with additional abrasives, such as sand, mixed into the rubber. Fibreglass ink erasers also work by abrasion. These erasers physically remove the ink and the paper it has marked from the larger sheet. The chemical ink eradicator contains a substance that reacts wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Telephone Card
A telephone card, calling card or phonecard for short, is a credit card-size plastic or paper card, used to pay for telephone services (often international or long-distance calling). It is not necessary to have the physical card except with a stored-value system; knowledge of the access telephone number to dial and the PIN is sufficient. Standard cards which can be purchased and used without any sort of account facility give a fixed amount of credit and are discarded when used up; rechargeable cards can be topped up, or collect payment in arrears. The system for payment and the way in which the card is used to place a telephone call vary from card to card. Calling cards usually come equipped with PIN for user protection and security. Most companies require user to enter the PIN before granting access to the calling card's funds. PINs often are printed on a piece of paper found inside the calling card's packaging. Once the users makes their first call, some companies offer the op ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gift Cards
A gift card also known as gift certificate in North America, or gift voucher or gift token in the UK is a prepaid stored-value money card, usually issued by a retailer or bank, to be used as an alternative to cash for purchases within a particular store or related businesses. Gift cards are also given out by employers or organizations as rewards or gifts. They may also be distributed by retailers and marketers as part of a promotion strategy, to entice the recipient to come in or return to the store, and at times such cards are called cash cards. Gift cards are generally redeemable only for purchases at the relevant retail premises and cannot be cashed out, and in some situations may be subject to an expiry date or fees. American Express, MasterCard, and Visa offer generic gift cards which need not be redeemed at particular stores, and which are widely used for cashback marketing strategies. A feature of these cards is that they are generally anonymous and are disposed of when ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scratchcard
A scratchcard (also called a scratch off, scratch ticket, scratcher, scratchum, scratch-it, scratch game, scratch-and-win, instant game, instant lottery, scratchie, lot scrots, or scritchies) is a card designed for competitions, often made of thin cardstock or plastic to conceal PINs, where one or more areas contain concealed information which can be revealed by scratching off an opaque covering. Applications include cards sold for gambling (especially lottery games and quizzes), free-of-charge cards for quizzes, fraudulent free cards encouraging calls to premium rate phone services, and to conceal confidential information such as PINs for telephone calling cards (otherwise known as recharge cards) and other prepaid services. In some cases, the entire scratchable area needs to be scratched to see whether a prize has been won—the card is printed either to be a winner or not—or to reveal the secret code; the result does not depend upon what portions are scratched off. In ot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
