The Lure of the Penny Black

Spink Auctioneers have written a nice article about the Penny Black stamp that was published in 2012. The article writes an important point where: One thing about the design which confuses many collectors is the significance of the two letters that appear in the lower corners. These are quite simply explained but of enormous importance to specialists. The Penny Black was printed from eleven separate printing plates, each containing 240 impressions arranged in twenty horizontal rows of twelve (12 pence = One shilling, 20 shillings = £1) which was important for Post office accounting purposes.

The stamp in the upper-left corner of the sheet had the letters AA in its lower corners, the next stamp was lettered AB then AC, AD and on to AL, the first stamp in the next row was BA, etc., down to the lower-right corner of the sheet which was lettered TL (below, a strip of four showing the different letters). So we can see that each of the 240 different combinations of letters are equally rare (or as common!). This was done as a form of protection against forgery as it was thought to be impractical for a forger to be able to reproduce 240 different combinations of lettering and it would be noticed if quantities of mail bearing stamps with the same letters were found. Where the letters are of great significance is in helping us tell which of the 11 (or twelve) plates a particular stamp was printed from. 

Every collector wants a Penny Black. A serious collector of Great Britain would like at least one from each plate. There are a few collectors who want to have examples from each of the 240 impressions from each of the twelve plates (That would be 2,880 Penny Blacks!). Credits: Spink London https://www.spink.com/research-articles/the-lure-of-the-penny-black.aspx