Many rare German stamps exist in private collections and museums. These stamps date back from as early as the mid 19th century to modern day misprints.
Rare German stamps originate from periods throughout the country's history, and their rarity can be attributed to numerous reasons.
Printing errors are one of the most significant causes of rarity. For example, the Baden 9 Kreuzer error, a stamp issued in 1851 by the German state of Baden, was printed on the wrong color paper. Only a small number of these stamps were printed erroneously, and there are only four known copies of the Baden 9 Kreuzer error in existence.
Shortages in stamps and printing materials also leads to the creation of rare stamps. A half of a stamp from northern Germany created during a stamp shortage in 1872 sold for $347,500 in 2010. Wars and other disasters that destroy most printings of a stamp make the remaining stamps rarer and thus more valuable. Rare stamps created with poor quality ink or paper date from shortages during the First World War.
Commemorative and limited edition stamps printed only in small batches may also become rare collector's items. A stamp printed in 1945 to commemorate the Nazi rise to power is very rare because it was printed for only a short period of time.