A Smilers generic sheet is to be issued to celebrate the 350th anniversary of the postmark.

It was Postmaster-General Henry Bishop who introduced a simple handstamp in 1661 which noted the date when a letter arrived at a post office, so that postmen would be encouraged to deliver the mail more quickly.

The sheet features 20 1st class Seal stamps, from the Business & Consumer Smilers set issued in 2010, alongside labels showing various landmark postmarks such as the original Bishop mark, the Maltese Cross, the squared circle and the first machine slogan.

The border includes a diagram of Pearson Hill’s cancellation machine.

Designed by Interabang and printed by Cartor Security Print by lithography, and will be issued on September 15, priced £9.50.