David Gentleman designed his first stamps for Royal Mail in 1962 (for National Productivity Year). Since then he has been the most prolific and acclaimed stamp designer in Britain, with 103 issued stamps to his name. These range from trains and boats and planes; to architecture, domestic and religious; flora and fauna; and representations of historical events, in a variety of styles. His latest issued stamps were in the "Millennium Timekeeper" miniature sheet of 1999.

Perhaps his greatest influence on British stamp design was the Album of experimental designs commissioned by Tony Benn as Postmaster General in 1965. In that, he vastly expanded the choice of possible subject matter and created a new shape for pictorial stamps. He also suggested that The Queen's head might be replaced by a Crown or Royal Cypher, but this was not accepted. However, Gentleman then created a small cameo head of The Queen instead of the awkward Wilding portrait and this became standard. These revolutionary designs were to influence British stamp design for over 20 years.

With his Social Reformers stamps of 1976, a particular favourite of his, Gentleman dramatised the harsh and repetitive conditions of factory workers, miners, prisoners and climbing children, underlined by the repeating patterns of a block or sheet of stamps. Original concepts from his own collection are shown here for the first time.

Many of Gentleman's commissions were not adopted for the final stamps. Sometimes, the proposed stamp issue did not take place. So, of the almost 1,000 sketches and pieces of artwork held in the Royal Mail Archive, most have never been seen before. A selection of this rich archive of unadopted stamp artwork is exhibited here for the first time.