Penny Black

"I know virtually nothing about the significance of particular check letters, plates, or the imprimatur sheet,"



The stamp above left ...a new issue from Royal Mail... has corner check letters S C and the letters can be matched with a known example of the plate used to print the original 1840 stamp. In this case the new stamp could be said to be plate 1a and it matches the 1840 stamp on the right. As all the letters were punched by hand in 1840 they will have slight... or even big... variations in position or orientation.
Every plate, when first used, had a sheet of 240 stamps kept for official reference and records and is known as an imprimatur sheet. Frequently some stamps were cut out of the sheet so that the imprimatur sheet is now incomplete. Your excellent stamp is from one of the missing positions... although it is unlikely that it is the actual stamp cut from the sheet... it is from that T A position so will have a premium added to the already quite nice value

This is your Penny Black T A alongside a known plate 3 T A

scotzm, thank you so much for taking the time to provide such excellent information regarding my Penny Black. I have saved it, including the side-by-side comparison images.

A pleasure to see a nice quality item like that one.
Should you wish to do a write-up on this Penny Black then you might wish to include the dot which is arrowed near the left star frame. These are "printers dots" and were used to aid the positioning of the transfer roller when setting out the plate. Normally they were burnished out but occasionally left as you can see. Both stamps have the "dot" there so that would also aid identification. Philatelically of interest and may even give even more additional monetary value.

Thanks again, scotzm.