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Protecting a Letter

On Techniques For Protecting The Privacy of a Letter


Methods for protecting the confidentiality of correspondence, from past eras and places, result in enchanting works of mystery and precision.

Few things are more intimate than a letter. Though we live in an age of email and text messages, nothing will ever be as personal as a missive written out on paper. It’s as if the simple fact of doing something with our own hands endows an object with a metaphysical quality which may even contain a little of the essence of the sender.

For centuries, letter writers have used various methods for keeping letters from being violated, with folds and cuts of paper, seals of lacquer or wax, threads and ties, and even stranger ways of hiding the secrets of kings and emperors, generals and soldiers. After all, they were messages on which important matters might depend, including people’s lives and the fates of nations.

To name but one example, on February 8, 1587, Mary, Queen of Scots, wrote to her brother-in-law what was to be her final letter. Just six hours later she was beheaded for treason, on the orders of her cousin, Queen Elizabeth I of England. The missive thus became one of the most valued objects in Scotland, a symbol of the country’s history and a poignant witness to a woman grappling with an inevitable death. To maintain this final letter’s privacy, the Queen used what was known as the “butterfly lock.” It’s one of hundreds of techniques studied for years by Jana Dambrogio, a curator at the Library of the Massachusetts Institute of Technology.

Dambrogio has dedicated the last decade of her life to studying the mechanisms and techniques used to secure correspondence throughout history and prior to the mass-production of envelopes (which are closed simply by wetting an edge stamped with glue). She’s currently preparing a dictionary of techniques for securing letters, and might be thought of as a private investigator of ancient and fascinating epistolary secrets.

Many other characters in history, beyond Queen Mary, resorted to techniques for the protection of correspondence. Among them are Machiavelli, Galileo, Marie-Antoinette, John Donne, and Albrecht Dürer, to name but a few. The practice accompanied written communications for centuries and the diversity of techniques, in all their ingenuity, is still surprising.

In the past, letters were often sealed such that the same sheet written upon became also an envelope. Depending on the desired level of privacy, a simple triangular seal might be used. For more security, one might resort to a dagger-trap seal. This one included cuts, folds, a thread securing the letter, and a lacquer seal. The characteristics of the technique constitute a trap because, at first glance, the seal seems simple. Any attempt to open the letter, though, could result in the easy destruction of the letter.

In the West, the practice of sealing letters began with the manufacture of flexible paper, around the 13th century, and ends with the mass-production of envelopes in the 19th century. But the long history (at least 10,000 years) of securing documents began with the clay tablets of ancient Mesopotamia.

Those currently studying the art of securing correspondence believe the techniques used have always spoken of the senders’ tastes and personalities, always revealing much about social status, rank, and issues of class. Moreover, some of the techniques for guarding a missive recall the fact that letters are treasures capable of saving lives. As mere objects, they’re endowed with a mysterious, fascinating, and often enough, an entirely secret power.


Image: Public domain

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