Part nine of the Scarsdale Collection will be offered at auction in New York on March 21, featuring a nearly complete representation of embossed stamped envelopes and postal cards, including the unique Die 56 3c green on blue.

The US' embossed envelopes provide one of the most challenging areas of collecting, with numerous varieties

The 3c green on blue is expected to sell for $125,000 when it crosses the block, as testament to its extreme rarity. According to the auction house, US embossed stamped envelopes and postal cards provide one of the most difficult areas in philately.

Stamped envelopes were issued as a result of the US Congress' request to provide "suitable letter envelopes with such watermarks or other guards against counterfeits... with the addition of the value or denomination of the postage stamps so printed or impressed thereon..."

The subsequent issues are defined by die type, colour and paper by collectors, resulting in numerous variations. The Scarsdale Collection encompasses almost all of these, as one of the world's premier holdings of its type.

Originating from the 1874-86 Plimpton Issue, which is named after the contractor responsible for production, the 3c green on blue is a cut square, taken from the top right of an envelope. There are no recorded entire examples of this extraordinary rarity and this is the only recorded cut square of its type.

The 1955 Barkhausen sale catalogue states that this unique example was known as early as 1908 and was noted by Dr Berthold as residing in the Ayer collection. It was then sold by the New England Stamp Company and ended up in the Hind collection.

The Scarsdale Collection has been offered through the same company since 2006, with part eight featuring Match and Medicine stamps.

Paul Fraser Collectibles continues to bring you all the latest philatelic news from around the world. We also have a spectacular holding of rare stamps for sale.