Letterlocking: Triangle lock-YU with slit parallel to the fore-edge, Europe and England (1560s-1700s)
This model of a 'triangle-shaped paper lock-YU with slit parallel to the fore-edge has features found on the most secure historic letters: the paper lock is cut from the same letter it is locking, the tapered end of the paper lock weaves through a slit penetrating all the panels of the folded letter, the sealing wax secures the lock in place, and the receiver must tear the paper lock to gain access to the contents inside. In the late-16th century this format was used by Venetian Tomaso di Levrieri (Vatican Secret Archives, Fondo Veneto, Sezione II, #670, letters to Gesuati priests, San Girolamo Monastery, Vicenza). Elizabeth I, Queen of England, her spymaster Sir Francis Walsingham, and Lord Burghley used this format in correspondence to Sir Rafe Sadler over the arrest of Mary, Queen of Scots in the 1580s (British Library, Loan MS 128, fols 41–48).
Some of the earliest known examples of locked paper letters are found in the Paston letters and date back to 1440 (British Library, Add. MS 43488). The earliest use of a 'triangle-shaped paper lock-N' documented in this study dates back to 1494 and is found in the Vatican Secret Archives (Fondo Veneto, Sezione II, #670).
Letterlocking refers to the act of folding and securing an epistolary writing substrate (such as papyrus, parchment, or paper) to function as its own envelope or sending device. Letterlocking is a sub-category of a 10,000-year document security tradition, ranging from Mesopotamian clay bullae (8,000 BCE) to Bitcoin paper wallets (2009). Letterlocking also refers to the discipline which studies the technologies and traditions of epistolary security and privacy. Documenting the physical details of well-preserved original manuscripts has helped to define the different locking categories with their multiple levels of built-in security and their various authentication devices. The categories may correlate to the sensitivity of the information contained inside.
Letters are a fundamental aspect of private and public record keeping. They may be gathered into bundles, tucked around something, or compiled into bound structures to keep related subject matter together. Letterlocking variations were used by Heads of State for ceremonial letter exchanges. Letterlocked documents are part of a larger study; they are one of 250 legal and accounting documents and bound record formats found in the Fondo Veneto Sezione II in the Vatican Secret Archives. (For example, see videos showing one of the book structures called a "filza".
Making models of historic originals is a necessary step in categorizing this fundamental communication technology to learn how locked documents once functioned as three-dimensional objects. A simulacrum is often the first type of model made and must be fabricated in the presence of the original manuscript in order to capture nuances (deliberate slits, folds, cut-off portions, etc.) found on the artifact. These models serve an important purpose because they help the observer catch details they may have otherwise overlooked while viewing only digital images of the original. They help to distinguish folds used for writing from ones used for sending, filing, or storing. Models serve as invaluable reference tools to consult away from the originals.
Understanding the minute physical details on the historic locked letters enable conservators to preserve the integrity of the originals so that the information is available for study and interpretation. The letter is the artifact, the witness to a specific historic moment; alter its physical evidence and the witness loses its voice.
Produced by MIT Video Productions (MVP). Directed and demonstrated by Jana Dambrogio, Thomas F. Peterson (1957) Conservator, MIT Libraries. Funded by MIT Libraries and Jana Dambrogio.
Special thanks to Ann Marie Willer, Preservation Librarian and Barry Pugatch, MVP staff.
Cite as: Jana Dambrogio, et al. ‘Triangle lock-YU with slit parallel to the fore-edge, Europe and England (1560s-1700s)’, Letterlocking Instructional Videos. Filmed: June 2014. Duration: 2:38. Posted: June 2014. Video URL: [Use URL below]. Date accessed: [Date].
Copyright 2016. Jana Dambrogio, Daniel Starza Smith and Massachusetts Institute of Technology (M.I.T). All rights reserved. The following copyrighted material is made available under the Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) License creativecommons.org/licenses/by-nc/4.0/. Contact the M.I.T. Technology Licensing Office for any other licensing inquiries.
NB: Letterlock responsibly. Be mindful of open flames or hot tools.
The URL for this video is: vimeo.com/letterlocking/TriangleLock