A set of 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 denominationEach individual value in a series of banknotes or coins. More, numbered from one to ten, showing different degrees of fitness, soilingThe process of staining, usually by greasy materials sticking to the surface or by the absorption and adhesion of dust and particles to the cotton fibres of which the banknote is made. It is one of the main reasons for banknote deterioration and their subsequent destruction. More level and wear and tear due to usage, representative of the changes in the condition and appearance of the banknote over its useful lifetime. It serves as a reference to identify the maximum level of soiling or impairment allowed and determines when a banknote should be removed from circulation.