The presidential seal () is a seal used by the President of Ireland to authenticate his signature on official documents. The Constitution of Ireland requires certain documents to be issued under the president's "hand and seal", and in other cases the seal is mandated by act of the Oireachtas. It is a single-sided "dry seal" impressed directly onto the fabric of the document, leaving a relief of its design without sealing wax or ink. Design The physical seal is a metal disc about in diameter. The image is an Irish harp, with 15 strings, surrounded by a ring of Celtic ornamentation based on that on the base of the Ardagh Chalice. Within the ring is the word ("Ireland", the name of the state in Irish) in Gaelic type. The design was approved by the Executive Council of the Irish Free State on 15 September 1937, in preparation for the adoption of the current constitution on 29 December 1937. The harp is modelled on the 1928 design by Percy Metcalfe for the obverse of the Free State coinage, itself based on the "Brian Ború harp", also used on the 1945 coat of arms of Ireland. The design is similar to that of the seal which it replaced, the Internal Great Seal of the Irish Free State; the most obvious difference being in the name of the state (previously ). However, the Free State seal was used with sealing wax. In 1949 John Aloysius Belton of the Department of External Affairs suggested changes to the seal's design to reflect its new diplomatic uses under the Republic of Ireland Act, but no change was made. Use The seal remains in the custody of the current President or, in his absence, the Presidential Commission. In the latter case, sealed documents must be signed by at least two members of the commission and the Secretary-General to the President. At the inauguration of a new president, the Chief Justice presents the seal to him. The 1937 Constitution of Ireland created the office of President of Ireland and defines most of its powers. It specifies several situations in which the President must send a message "under his hand and seal": notifying the Oireachtas (parliament) of agreeing or refusing to an ordinary referendum appointing or dismissing discretionary members of the Council of State dismissing (after impeachment) the Comptroller and Auditor General or a judge It specifies other cases