The set of six marking the centenary of Nobel Prizes broke new ground in that each used a different printing technology. The 40p, for example, was a scratch-and-sniff stamp and the 2nd class changed colour when exposed to heat. But the star was the 65p, Britain’s first holographic issue.

In honour of the Physics prize, the design is of a Carbon 60 molecule, which is quite eye-catching in itself. But when you tilt it you see an image of a molecule of boron with its electrons orbiting in all the colours of the rainbow.

It was a pity that, as the highest value, this stamp was seldom seen on mail. But we can still marvel at the technology behind it.

Design: HGV Design.

Printing: lithography with holographic foil by Enschedé.