 Postgate wrote "Alexander The Mouse," a story about a mouse born to be king.Using an Irish-produced magnetic system – on which animated characters were attached to a painted background, and then photographed through a 45-degree mirror – he persuaded Peter Firmin, who was then teaching at the Central School of Art, to create the background scenes.Postgate later recalled they undertook around 26 of these programmes live-to-air, which were made harder by the production problems encountered by the use and restrictions of using magnets.