Ink scheme to stamp out cheats

Stamps are to be daubed in phosphorescent ink to help save the Post Office money.

The ink will allow sorting machines to pinpoint where stamps are on envelopes and packages and make sure they are post-marked. Stamps will carry one or two colourless phosphorescent bars, which can be detected by ultra-violet light.

A spokesman said the Post Office wanted to make sure stamps could not be used more than once. Money had been lost in the past because postmarks did not always properly cover stamps.