Art style more reminiscent of US rather than UK - even Soviet to a degree. ("World War Two poster calling for female factory workers. Published in 1941 by the British Ministry of Information. Artwork by Donald Zec")
'Keep Calm and Carry On' posters were produced by the British government in several months before the beginning of the Second World War, to raise the morale of the British public in the aftermath of widely predicted mass air attacks on major cities.