
1 d Penny Black stamp lettered G-G, identified as coming from plate 9 using Guide Lines to the Penny Black by P C Litchfield.
Period of use: Earliest issue dated 18 November, 1840. Plate used very briefly until January 1841 making this fairly scarce.
Colour: Strong black.
Cancellation: Clear Maltese Cross cancellation in black ink (plate 9 is found cancelled in both red and black ink – neither is more common).
Main identification clues:

Vertical guidelines in the right hand letter square and NE square (very common on this plate).

“O flaw”, stage 2.