抄録
Paper money was born as a substitute for metal money in distant commercial transactions. With its denominations eventually becoming fixed numbers, it developed into a currency used by a large number of unspecified people. As the circulation of paper money increased, counterfeiters began to try their hands at producing more. Anti-counterfeiting measures became an important factor in paper money production. Anti-counterfeiting technologies have been improved dramatically over the years: today, color- and pattern-shifting elements are used to make counterfeiting harder and counterfeited money easier to spot in a new technological environment.
