Printed in March 1840, two months prior to the release of the Penny Black, the die proof was produced to check that all the details in the design would print correctly before the stamp went into production ready for its release on 6th May 1840.
The Penny Black went on to revolutionise the world; by the end of 1840 over 160 million letters had been sent all over the world, doubling the number from the previous year.
As the stamp had originally been intended only for domestic use it did not include the country name in the design. To this day Great Britain is the only country in the world not to have its country name on its stamps and this history can be traced back to the die proof offered for sale by Stanley Gibbons.
With a print run of approximately 68 million the Penny Black is not rare; however a used example is currently catalogued at £350, showing an average compound growth of 11% over the past decade.
Described as being in exceptional condition- the other example in private hands, owned by the Earl of Crawford, is somewhat flawed in comparison and the three remaining examples are in institutional collections;
The Penny Black Master Die Proof is currently for sale for £350,000.