 The first miniature sheet of four stamp on stamp postage stamps was issued in 1972 to commemorate the 50th anniversary of the first Irish postage stamp . This was followed by a four @-@ stamp sheet to commemorate the bicentenary of the United States Declaration of Independence ; the stamps in this sheet were also available as single stamps . A set of four stamps showing Irish wildlife was issued in sheet form and also as single stamps in 1980 . 
