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Yellow dots on white paper, produced by color laser printer (enlarged, dot diameter about 0.1 mm) Printer tracking dots, also known as printer steganography, DocuColor tracking dots, yellow dots, secret dots, or a machine identification code (MIC), is a digital watermark which many color laser printers and photocopiers produce on every printed page that identifies the specific device that was ...
True watermark. A true watermark is a recognizable image or pattern in paper that appears lighter or darker than surrounding paper when viewed with a light from behind the paper, due to paper density variations. A watermark is made by impressing a water coated metal stamp or dandy roll onto the paper during manufacturing.
Barack Obama's birth certificate on 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.
The resulting watermark is generally much clearer and more detailed than those made by the Dandy Roll process, and as such, Cylinder Mould Watermark Paper is the preferred type of watermarked paper for banknotes, passports, motor vehicle titles, and other documents where it is an important anti-counterfeiting measure.
The EURion constellation is made up of five rings. The EURion constellation (also known as Omron rings [1] or doughnuts [2]) is a pattern of symbols incorporated into a number of secure documents such as banknotes, cheques, and ownership title certificates designs worldwide since about 1996.
Paper-makers – When the watermark documents the papermaker's name, the trade name of the paper or in some instances the stamp contractor or printer. These are similar to sheet watermarks. For example, the "Harrison & Sons, London" watermark used for Maldive Islands 1933 issue.
A number of authentication systems are known by the general term of "watermarking" methods, since they rely on embedding authentication information into another information bearer, by analogy with the watermarking of paper.
Color copiers and maybe some color computer printers steganographically embed their identification number as a countermeasure against currency forgeries. Copiers and computer printers can be potentially identified by the minor variants of the way they feed the paper through the printing mechanism, leaving banding artifacts.