The design for a definitive stamp is usually used for a decade or more. For example, the national flag stamp was first issued in 1978. Although the price on the stamp was changed over time with each increase in rates, the flag design remained the same.
常用票圖案經常一用十幾年，以民國六十七年發行的國旗郵票為例，因應郵資調漲，郵票面額幾度調升，但依舊沿用國旗圖案。