Certain substances, special elements or hard-to-reproduce printing processes that are incorporated into a banknoteA banknote (or ‘bill’ as it is often referred to in the US) is a type of negotiable promissory note, issued by a bank or other licensed authority, payable to the bearer on demand. More during its manufacture for the purpose of making it difficult to counterfeitThe reproduction or alteration of a document or security element with the intent to deceive the public. A counterfeit banknote looks authentic and has been manufactured or altered fraudulently. In most countries, currency counterfeiting is a criminal offence under the criminal code. More and to facilitate its recognition. Examples of widely used security features are the following: intaglio-printing, ink layer with embossed relief, watermarks, threads and foils, matching motifs and optically variable elements such as holograms and optically variable inks. These are verified through looking, feeling and tilting or by instruments such as magnifying glasses and ultraviolet lamps. Some features are designed for detection by sensorsDevices capable of detecting specific physical properties of banknotes. More integrated in machines for verifying and processing banknotes.