If you have ever wandered around London as a tourist, I’m sure that at some point you noticed the ubiquitous blue ceramic plaques around the city noting where famous historical figures lived or worked. The iconic plaques commemorating figures as diverse as Jimi Hendrix and Karl Marx or Keith Moon and Sigmund Freud are administered by the English Heritage organization.

I was surprised to discover that each plaque has been produced by the same family since 1984. The charming little film below, directed by Cat McShane, explores the process behind the creation of the blue plaques. You can find ever single blue disc at the Open Plaques website.