 For coins only, the U.S. Treasury received 45 cents per dollar issued in seigniorage for the 2011 fiscal year.Occasionally, central banks have issued limited quantities of higher-value banknotes in unusual denominations for collecting; the denomination will usually coincide with an anniversary of national significance.The potential seigniorage from such printings has been limited, since the unusual denomination makes the notes more difficult to circulate and only a relatively-small number of people collect higher-value notes.