The Two Penny Blue was the world’s second official postage stamp, issued after the Penny Black.
It was issued in the United Kingdom of Great Britain and Ireland and was first sold to the public at the London Inland revenue office in the afternoon of May 8th 1840. Except for its denomination of the design is exactly the same as the 1d black and was struck from the same die. [1]
It was intended that the 2d blue was to be issued at the same time as the 1d black, however there is doubt about this - the earliest post mark seen on one of these was the 8th of May 1840, two days later than the Penny Black. The first issues of this value (intended for double rate letters), were printed from plates 1 and 2. Copies of the stamp are now significantly rarer and more expensive than the Penny Black.
Later when the colours of the stamps were being revised, the inks chosen were red-brown for the penny value and a new blue ink for the two pence value. As the printed stamps in the new ink looked the same as the original issue, it was decided to add a horizontal line at the top and bottom of the label so as the newer printings could be easily identified. These are generally referred to as the white lines added issue, as is pictured here. They are commoner than the original 1840 printing.
The Penny Black allowed a letter weighing up to half an ounce to be sent anywhere within Britain; the Two Penny Blue's weight limit was a full ounce. [2]