Postal Orders. 
Let us suppose you want to respond to an ad in the paper and send in three shillings, nine pence. The shilling coin is similar to a US quarter, the six pence about the size of a dime, and the pennies about the size of a silver dollar. Tape them to a piece of cardboard, and put in a heavy envelope. The cost to mail it may be more than 3’9d due to weight. Another option is to purchase a money order. This is better, but the money order fee will increase the cost more. The way this was handled was to purchase a postal order, sometimes called a postal note.
A postal order is a document of fixed value. Many different values are available. When issued, the postal clerk stamped the left block with his canceller. The 1 shilling example shown in Figure 1 is a one shilling note from Straid Laighlan (Leinster Street) Post Office in Dublin in 1956. The cost was 1’2d. The sender would remove the receipt on the left, and mail it to the recipient. The recipient would bring the postal note to his/her post office, sign in the lower left to acknowledge receipt of money, the clerk invalidated it by cancelling the left square, and it was filed.
The designs of postal orders varied over the years. Figures 2-7. Different designs and colors were used for various years, and for the different governments, ie, the Provisional Government, the Free State, and the Republic.
8 July 2018