Most collectors of the British Machins may not be interested in the variation in the direction of printing. With the introduction of denominated self-adhesives, it was found that first day covers were a source for one such variety. Special strips of stamps were produced to service these covers. Whereas the sheet and booklet stamps had been printed upright, the strips of stamps used for first day covers had been printed sideways.
The new, bigger Machins with matrix code were printed sideways. First day covers could no longer be the source for varieties. Or could they?
Yesterday, I received my first day covers for the 'Jennings' permanent stamps for make-up values. A philatelic blog pointed at a variety that occurred on first day covers. It is a very visible variety, or an error. Because this is so striking, collectors may want to buy first day covers to own the variety that occurs on all stamps issued on 29 August 2023.


The stamps do not have the usual security slits that should destroy the stamps when taken from a cover for illegal reuse. The bad news for those who hope their used stamps no longer will be damaged is that this appears a to be a special printing - probably the usual strip – for first day covers.
I ordered my stamps only yesterday. So, I cannot show a scan of them. But images on the web and this publicity material posted by philatomic in another thread all show the security slits.


By the way, sheets of these stamps already had been printed in February. They, officially, were released on 29 August 2023. It appears some post offices that had run out of stock of Machins sold some of the stamps early.