This Paraguay stamp, #562, features a double overprint with one of the overprints being upside down, resulting in a rare and unique error.
The stamp is in mint condition, never hinged, and is of fine to very fine quality. The centering and straight lines can be judged from the provided scans.
Please note that the numbers in parentheses are inventory control numbers and do not affect the v…

This stamp from Bhutan is a rare and unique find for collectors of stamp errors and oddities.
The 70 Chetrums mask stamp features a helicopter design with an overprinted "INVERTED" label, making it a major error that is highly sought after.
The stamp is in mint condition and features a picture of a Bhutanese mask uniform. It is a guaranteed genuine item that is sure to appreciate in value…