The first heat sensitive stamps ever issued in Great Britain has been released by Royal Mail. The cloud design on the new range of stamps will change from a grey to blue if it is rubbed.

The range of weather stamps were released on March 13, 2001 to mark the 150th anniversary of weather maps going on sale.

Thermochromic ink enables the cloud on the stamp to change from a dark and gloomy grey to sky blue when touched.

Mark Thomson, managing director of Royal Mail stamps and collectables, said: "We feel the stamps capture the wide range of weather conditions in Britain.

"Each stamp is a segment of one complete image - bringing all four together creates the dial of a barometer."