One of the more colourful aspects of a Machin collection are the prestige booklet panes. They are a visually attractive addition to more samey items like cylinder blocks etc. The one shown here is of course even more interesting because it is from the prestige booklet issued to mark the 40th anniversary of the Machin stamp. It shows the master himself.
On these panes you will usually find nice se-tenant pairs and varieties of stamps that occur in no other format. That goes for this one too. Here is an image of the 2p sheet issue.
Now if you look closely you will see that the value has been redrawn for the prestige booklet. It is "much" thicker. My eyesight sometimes fails me when details like these are concerned but if you look carefully at the "p", you'll see the difference.