Renaissance letter-writing is being re-examined using Digital Humanities tools to explore letterlocking techniques of securing correspondence.
The New York Times explains: “To safeguard the most important royal correspondence against snoops and spies in the 16th century, writers employed a complicated means of security. They’d fold the letter, then cut a dangling strip, using that as an improvised thread to sew stitches that locked the letter and turned the flat writing paper into its own envelope. To get inside, a spy would have to snip the lock open, an act impossible to go undetected.”
Historians who study the Renaissance using manuscript correspondence will certainly recognize the signs of letterlocking in archival collections. Letters that were received and opened during the sixteenth century have the pierced holes and sometimes fragments of the strips of paper that formed the spiral locks.
Letterlocking provided a certain level of security for correspondence, allowing recipients to recognize that the letter had not been opened in transit. Other security techniques utilized in Renaissance correspondence included encryption, secret ink, and oral transmission by couriers. Historians, archivists, and librarians have been studying all of these techniques and broader the material culture of letter-writing for some time.
A research team at M.I.T. has been digitally modeling letterlocking techniques and analyzing letters written by Queen Elizabeth I of England, Mary Queen of Scots, and Queen Catherine de’ Medici of France. What is new here is the use of Digital Humanities tools in conjunction with the material culture methodologies. The M.I.T. team’s major new approach is to scan unopened letters and digitally “unfold” them.
One of the letters analyzed by the M.I.T. team is a letter by Queen Mother Catherine de’ Medici written in 1570.
The M.I.T. team has published their findings in several articles and has created a video (available on YouToube) to demonstrate letterlocking techniques:
The New York Times reports on the M.I.T. reseach project on letterlocking.
Previous reports by The New York Times, NPR, and the BBC have discussed the M.I.T. project and Mary Queen of Scots’ use of letterlocking.
The M.I.T. team has published their findings in several articles, including:
Dambrogio, J., Ghassaei, A., Smith, D.S. et al. “Unlocking history through automated virtual unfolding of sealed documents imaged by X-ray microtomography.” Nature Communications 12, 1184 (2021).