The 1990 set of four which set out to tell the story of astronomy featured arguably the most intricate designs ever issued by Royal Mail. The 31p, concentrating on advances in observation, is a veritable feast for the eyes.

At the bottom centre it depicts the old Royal Observatory with the Greenwich Meridian running through it. Above this is part of a medieval star map, showing parts of the constellations Sagittarius and Scorpio.

On the right we see one of John Harrison’s chronometers, and to the left a clock and a mural quadrant. Arcing over all this are the planets, from Mercury out to Uranus.

Design: Jeff Fisher. 

Printing: offset lithography by Questa.