Postage Stamps with Errors

Some of the most sought after and highly valued postage stamps are those that have errors in their printing.
The stamp illustrated below is an example of this kind of stamp. The stamp was issued for use in India during the reign of Queen Victoria for the Indian Convention State of Patiala (originally overprinted "Puttialla"). Stamps used in the States were a standard stamp used throughout the Convention States overprinted with the name of the individual State.
Normally printed  "Puttialla" some of these stamps were overprinted "Auttialla". Illustrated below is an example of the blue-green half anna of 1885 overprinted in red in the type 2 overprint as listed in Stanley Gibbons.