Key type stamp
Key type stamps are stamps of a uniform design that were widely used by colonial territories in the 19th and 20th centuries.
Origins
The idea was invented by Perkins Bacon who used it to print stamps for Trinidad, Barbados and Mauritius, all featuring the same Britannia design.Key plate stamps
The idea was refined by De La Rue in 1879 when the printing process was split into two through the use of a key plate for the bulk of the design and a separate duty plate for the name of the colony and the value. These are often known as key plate stamps. While key type stamps are always of one colour due to being printed with a single plate, key plate stamps are printed with two plates and so can be printed with two different inks. This method has the advantage that most of the design remains the same in each variant of a stamp series with only the values, names and colours changing.Key plate stamps were used extensively by Great Britain, Germany, France, Spain and Portugal.