Euro banknotes a common theme of European architecture in various artistic eras. The obverse of the banknote features windows or gateways while the reverse bears different types of bridges. The architectural examples are stylised illustrations, not representations of existing monuments. All the notes of the initial series of euro notes bear the European flag, a map of the continent on the reverse, the name "euro" in both Latin and Greek script (EURO / ΕΥΡΩ) and the signature of a president of the ECB, depending on when the banknote was printed. The 12 stars from the flag are also incorporated into every note.
Euro banknotes are issued and printed in various member states. The euro banknotes are pure cotton fibre, which improves their durability as well as giving the banknotes a distinctive feel. They measure from to and have a variety of colour schemes. The euro notes contain many complex security features such as watermarks, invisible ink, holograms and microprinting that document their authenticity. While euro coins have a national side indicating the country of issue (although not necessarily of minting), euro notes lack this. Instead, this information is shown by the first character of each note's serial number. According to European Central Bank estimates,