20 Pounds

The Central Bank of Ireland took its printing operations in-house during the 1970s, and this series reflects that transition — produced entirely at the Dame Street facility rather than contracted abroad as earlier Irish issues had been. Bringing security printing under state control was a deliberate policy shift, not simply a cost decision, coming in the decade when counterfeiting of high-denomination notes had become a growing concern across Western Europe.

Three signature combinations across twelve years of issue means dating individual examples is straightforward from the signatures alone, without relying on the printed date. The Doyle & Cromien pairing ran the longest of the three.