Broken Glass (1973)

While 'Charley Says', 'Splink' and 'Lonely Water' may remain among the most famous COI (Central Office of Information) films, the films were at their best when the output was at its simplest. 'Broken Glass' eschews animated cats, complex acronyms and the Grim Reaper in favour of a brutally minimalist approach, and is all the more effective for it. (Alex Davidson)

All titles on the BFI Films channel are preserved in the vast collections of the BFI National Archive. To find out more about the Archive visit http://www.bfi.org.uk/archive-collections