GB 1841 Penny Red Missing Imprimatur

Amongst a small group of Penny Red stamps recently acquired I have this little beauty from 1841 (left stamp)



Plated to plate 97 and with the check letters H K it means the stamp is one of the "missing imprimatur" stamps...(every new plate had a sheet of stamps sent for approval and these were called imprimatur sheets and were kept for reference and other purposes. Some sheets had a few stamps removed for some reason or other so that many sheets were now incomplete. In the case of Plate 97, the stamps HJ, HK and HL were removed).
My stamp on the left side coincides with the right hand stamp which is an example of another Plate 97 H K taken from the online imprimatur database.

They do look like a match.

So your stamps aren't the ones removed from the imprimatur sheets but match the letters of ones that were removed?

I believe he means it is one one of imprimatur sheet stamps.

Finding the ACTUAL stamps cut from the imprimatur sheet would be an almost impossible task but they do exist because printers, officials kept them and perhaps noted their receipt in their records. They would be incredibly expensive. Imagine ONE Imprimatur Sheet having ONE stamp cut out.
The cut out stamps were from a single sheet that was meant to be kept for reference purposes. For all sorts of reasons (colour check, paper check, favour to a collector etc) some were cut from that one and only reference sheet and so, with the official sheet being now incomplete, no official record exists of the stamps at that cut location. The "missing imprimatur" label can be used to refer to stamps that have been found to be from other sheets, printed by the same printing plate, at that cut location.



http://www.maltesex.com/missing_imprimatur/
is a good place to identify missing imprimatur stamps

I found three examples of missing imprimatur H K stamps like mine.

"ones that were removed".... I believe these would be officially termed "Removed" rather than "Missing" with the removed label being the actual stamps usually museums, royalty have those.

Thanks Scotzm for posting an interesting topic!

It is interesting that knowing the printing plate of a stamp you can get so much more information. Normally a Penny Red stamp like that might be written up as an 1841 Penny Red Imperforate S.G.8 and left at that. With further investigation... and hopefully my efforts are correct... I can tell that my stamp is from Plate 97, Die 1, Alphabet 1 and that the plate was registered in December 1849 so was probably printed in that year or 1850 depending on how long the plate was used. Also that 21 stamps were "removed" from the Imprimatur Sheet and my stamp is an example of a "missing imprimatur" stamp at position H K... same plate, same location.

Yes very interesting! (and what a gorgeous stamp )

The amazing thing is that, 170 years on, there are still corrections being made to the identifications of the "missing" stamp positions.

What a hobby.

I am wondering how you plate these. They didn't add plate numbers until 1864 when they started using letters in all 4 corners.

There would have been 1000's of sheets printed from each plate, each one of those sheets would have contained every position.

Pagoda

Bill:
You can plate the stamps by noticing the variations in the letter sizes and positions, frame lines that might extend a bit in one direction or another, guidelines that might have remained on the plate after it was readied for printing, burrs, or other marks.

The imprimatur sheets - early prints that were registered and archived - are the raw material that people studied. From them, the plating characteristics were noted. If a stamp was removed from the imprimatur, that was a "missing imprimatur." To get the plating characteristics, you'd have to start with a multiple that included a position you could match to one of the sheets. The other positions would then go into the database and allow you to match an individual stamp later, as was done in the case of the original post here.

If you want to get an idea of the challenge, Nissen did a reconstruction of the first 12 plates (1a, 1b, 2-11) that was sold as a set and archived on the Spink website.
This link will take you to the page:
https://www.spink.com/nissen-reconstructions.aspx
You can call up any letter combination and see stamps from the different plates. For the penny black plates, there are some underlying characteristics that narrow the ranges - plates 8-10 have what is known as the "O" flaw - a white area at the bottom under the "O" of ONE. Plates 1a, 1b, and 2 have various "ray flaws." and so on. There are other things that help narrow the range of the later plates, such as the gap at the top right on plates 16-24 that widens as you get later in the range. Plating is something of an art and requires both the reference material and a good eye.

Chip
Thank you for that link. Another way to fill in my evenings beckons!n Some of the research work undertaken by individuals, essentially as a means of passing time, is quite remarkable.

Geoff