The four sheets of 50 stamps are printed on one press plate, shown by the grid positions in the lower left corner:
The supplies we have are with black plate (they aren't cylinders) C1, dated 10/07/12. As mentioned previously, Cartor cannot print the date with an ink-jet add-on, so the date is on the plate. We have already shown the Wales 1st class and England 2nd class from C2 dated 11/07/12. The Scotland 1st & 2nd also exist with two printing dates, but we cannot yet confirm that the plate number was changed. When the 87p Wales stamp was reprinted on 02/07/12 the plate number remained C1 although it was clearly a new black plate.
So here for comparison are the De La Rue printings* (on the left) and the new Cartor printing on the right. As you can see the Cartor have much more yellow in them. You may recall that when De La Rue reprinted the Wales 1st there was too much yellow, and so the yellow was dropped and two black cylinders were used, although the later print has never been distributed by Royal Mail Tallents House and is not separately listed in Gibbons' Concise catalogue (W99 is still listed as being 'blue-green, greenish-yellow, silver, and black).
* The DLR stamps shown here may not be their most recent printings. I took these from stock and they are the latest ones we bought from Tallents House. Other printings may have shade differences, but probably not as marked as these.
ENGLAND - De La Rue v. Cartor
WALES 2nd - De La Rue v. Cartor. As well as having more yellow, the Cartor printing is much sharper, especially around the value. However, some parts of the leek are lacking the detail (black) in the DLR print.
I've shown the two De La Rue printings side-by-side before. I think it is clear from these pictures that the original DLR has yellow in the dragon, but the dragon on the Cartor printing - although lighter than either DLR printing - shows no yellow, and it only appears in the green background.
So as to keep everything together, the Scotland 1st & 2nd are reproduced again, with DLR on the left:
* UPDATE: The England and Wales stamps will be available from Tallents House from 3 January 2013 and are being distributed with the new colour Machin definitives. I'm presuming they will be distributed on Standing Orders where appropriate.
Stock codes are:
ES501 - England 2nd
ES601 - England 1st
WS501 - Wales 2nd
WS601 - Wales 1st
Apologies for not mentioning this before.