What is an imperforate stamp?
Perforations are the rows of small holes which allow stamps to be separated easily. Not all stamp sheets are issued with perforations between the stamps; stamps which lack perforations are termed “imperforate.” The first postage stamps issued by many countries, including the United Stamps, were imperforate stamps (the stamps were separated with scissors or by tearing along a metal straight edge). Modern imperforate stamps are generally issued with collectors in mind- they are often issued in much smaller numbers than the same design with perforations.