So . . . you are writing a letter -- and naturally you don't want it to be read by the general public. But envelopes haven't been invented yet. What to do?
Mary Queen of Scots had that problem on February 8, 1587. She was writing a letter to her brother-in-law, Henri III, King of France. It was her last letter, as six hours later, she was executed.
Many other persons, such as Galileo and Marie Antoinette, along with those less renowned, had the same problem. The solution? Letterlocking.
The term was coined by Jana Dambrogio, the Thomas F. Peterson conservator at the Massachusetts Institute of Technology (MIT) Libraries. It refers to the many different ways that letter-writers folded and wrapped and sealed their missives to deter prying eyes.
A recent article in Atlas Obscura traces Ms. Dambrogio's career, from the Vatican Secret Archives, where, fresh out of grad school, she started noticing slits and fold marks and wax seals on the old letters. She gradually realized that she had founded a new area of research.
She has spent almost two decades figuring out the locks worked. It hasn't been easy. Most of the methods damage the letter when it is opened, bearing witness to spying – but also obscuring some of the techniques.
In 2012, a treasure trove of old letters, including 600 that have not been opened, was found in the Netherlands. In those days, the recipient paid the postage; so the postmaster held onto the letters, hoping that some might be claimed and the postage paid. This horde is being analyzed by Ms. Dambrogio and a collaborator, Daniel Starza Smith. It could take years.
In the meantime, they create replicas that they hand out at their workshops, teaching history and conservation to young and old.
As you can see by the photo, I've been trying out some of the techniques from instructional videos. It's fun!