Further refining the “colour separation” techniques used in Rainbow Dance, Lye feeds into the printing process off-cuts from GPO Film Unit documentaries. There are glimpses of men loading cargo, welding, and sorting mail, all transformed by Lye’s camera and paintbrush into a magic kingdom of colour and rhythm. The film implores viewers to keep Britain working efficiently by posting items before two o’clock in the afternoon; good advice still.

Geoff Brown