Postal Cards. 
Postal cards are government-issued cards with the postage printed on the address side. These are sometimes used by businesses for advertising and regular customers use them to jot a quick message. (Figure 1).
Another type of postal cards are those used by the Irish Post Office and An Post to announce special events to their customers. The stamp printed on the card may be slightly different in size or detail, and there are no perforations. Other cards are entirely new designs not reflected in the stamp program. Three examples shown here are a special event for the joint issue of the immigration stamp with the United States (Figures 2A&B); St Patrick;s Day (Figures 3A & B) and Christmas (Figures 4A and B).
Postal Stationery of Ireland, FAI Volume 30, and 2006 Supplement.