Santa's on strike! This charming animation for the GPO advises early posting to keep Father Christmas onside.

Posting early for Christmas is more serious than you thought - failure to do so might send Santa on strike! This delightful silhouette animation may not be the most logical argument for helping the Post Office out (does Santa deliver cards, and if he needs people to post presents then what does he do?) but who cares when it's so charmingly packaged.

By the time this public information short was released, German animator Lotte Reiniger had been making silhouette films for 30 years. Her 1926 masterpiece The Adventures of Prince Achmed remains a landmark of cinema history as the world's earliest surviving animated feature. Having first arrived in London in the late 1930s she produced some advertising films for the GPO Film Unit. After the war she returned to Britain and established Primrose Productions with her husband and creative partner Carl Koch (a writer and director who had worked as an assistant to Jean Renior) and Louis Hagen Jr - the son of the banker who had financed her 1926 feature.