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Varieties and subtypes are grouped by country and year of issue. Select the country and time periods by using the navigation tree on the right.

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Varieties are stamps that differ in detail from the ordinary issue and occur unintentionally. For the purposes of studying, the varieties are classified in two major groups based on the nature of their occurrence: constant and coincidental.

While varieties are unintentional, some postage stamps differ from regular issues in details that are produced intentionally, or at least knowingly, in only one part of the issue. These stamps are called subtypes.

Constant varieties

Constant varieties are stable and occur regularly in the same position on the sheet throughout one or more printings. In the majority of cases it is possible to determine the exact position of the variety on the sheet and also to assess the possible quantity printed. Constant varieties are:

  1. Plate errors and retouches
  2. Errors in overprint

Coincidental varieties

Coincidental varieties are non-uniform and ephemeral. As they occur through coincidence each case appears to be unique. It is not possible to assess the quantity that appeared in circulation nor to make a complete detailed list of them as they can appear in countless shapes and forms. Coincidental varieties appear in all stages of production. Coincidental varieties are:

  1. Coincidental printing errors
    • Offsets
    • Shifted print phases
    • Missing print phases (e.g. missing color or untagged)
    • Donuts
    • Wrong color
    • Poor quality colors
    • Inversion of center or frame
    • Double print
    • Printed on the gum side
    • Ink smears
  2. Coincidental overprint errors
    • Inverted overprint
    • Shifted overprint
    • Tilted overprint
    • Wrong overprint
    • Offsets
    • Overprint on the back of the stamp
  3. Coincidental perforation errors
    • Perforation shifts
    • Imperforations
    • Part perforations
    • Double (or even multiple) perforation
    • Mixed perforations
    • Blind perforations
  4. Coincidental paper errors
    • Paper creases and fold overs
    • Paper with wrong watermark
    • Inverted or flipped watermark
    • Shifted watermark
    • Damaged watermark


Subtypes are stamps that differ from regular issues in details that are produced intentionally, or at least knowingly, in only one part of the issue. The exact position on printed sheet can be determined, as well as the possible quantity printed. Subtypes are:

  • Engraver's mark (if present on only a part of issued stamps)
  • Head to tail stamps
  • Special engravings (for example to distinguish stamps between runs)
  • Other subtypes that result from the manner in which printing plates were produced