Joint Issues. 
Joint issues are when two or more nations agree to use the same stamp design on their nations stamps which are usually issued simultaneously. The Europa stamps of the members of the European Economic Community, also known as the Common Market are one of the longest lasting stamps sets of this type. Ireland joined the Europa stamps in 1963 with annual stamps designed to a common theme. (Figure 1).
Ireland has also shared stamp designs in joint issues with the United States, (Figure 2) Canada, Belgium, Faroe Islands, Iceland, Germany, India, Australia (Figure 3) and Mexico. (Figure 4)
Although not joint issues since the artwork is dissimilar, Ireland has commemorated the same people and events with France, Norway, Chile and several other countries on bi-lateral or multi-lateral basis.