 Between 1907 and 1916 , Sinn Féin , one of the nationalist organisations of the time , issued propaganda labels symbolising Irish nationhood . Their use as stamps was forbidden by Post Office regulations . The first design was a Celtic Cross , similar to one later adopted for two definitive stamps of 1923 , and the second depicts a female figure and harp in an oval frame . In 1912 , labels inscribed " Imperial Union " appeared , with a design of a larger harp and female figure . These labels , expressing unionist sentiments , are believed to have been printed in Manchester as a counter to the Sinn Féin labels . After the Home Rule Bill for Ireland was passed in parliament , an Irish Republican body issued labels in 1916 with the portraits of three nationalist heroes known as The Manchester Martyrs against an Irish tricolour background . Forgeries of these labels are common . Following the Easter Rising of 1916 , American sympathisers printed eight <unk> <unk> labels showing portraits of seven prominent leaders and a harp and shamrock label . The misspelling <unk> for <unk> could have been because of hasty preparation . 
