

Spotting royal cyphers with AI.
Originally published
May 6, 2023
We took FieldDay on a walk in the country to build an educational camera app around icons of British design.
The city many of us at New Material call home, London, is full of incredible history. One of the things I love most about living here is how many ways there are to explore it. There's the legendary 'Blue Plaque' scheme, the 'Hidden London' tours by the Transport Museum, and plenty of niche hobbies that have developed. 'Mudlarking' for example, which involves the use of metal detectors to separate piles of bottle caps from the occasional Roman within the sludge of the bank of the Thames.
My favourite of these activities however is called 'cypher-spotting'.
The Postal Museum defines this hobby as …
… the act of searching for different royal cyphers on letterboxes, to discover which British monarch’s reign they are from.
After discovering this, I quickly became obsessed. Few things compare to the thrill of spotting a rare Edward VIII cypher — except perhaps stumbling across one of the mere 300 surviving hexagonal postboxes designed by John W. Penfold.
With the upcoming coronation of King Charles III and the introduction of a new royal cypher, I saw an excellent opportunity to bring this excitement to more people.
Building the model
On a bright Saturday morning I got into my car and drove to the Cotswolds. Some of the best postboxes can be found up there.
