Thursday 10 June | 18:00-20:00 | Online


Before the invention of the gummed envelope in the 1830s, almost all letters were sent using letterlocking, the practice of folding and securing a writing surface to become its own envelope. Based on 20 years research into 250,000 letters, this talk and workshop will present our main findings, including information about the letter we “virtually unfolded” in a recent Nature Communications article.

There will also be an opportunity to do some letterlocking yourself! Please bring some paper (printer paper is fine), scissors, some stickers or sticky tape (colourful kids’ stickers are most fun), and some sewing thread.

You may also wish to check out, and our YouTube channel:

Jana Dambrogio is the Thomas F. Peterson (1957) Conservator for Massachusetts Institute of Technology Libraries. She previously held positions at the US National Archives, the United Nations, and the Vatican Apostolic Archives. Her research in letterlocking has been supported by the Seaver Institute, the Delmas Foundation, and the American Academy in Rome. Her 2017 essay ‘Trickett’s Tickets’ reveals the identity of the first bookbinder for the US Continental Congress, William Trickett. 


Daniel Starza Smith is Lecturer in Early Modern English Literature (1500–1700) at King’s College London. His books include John Donne and the Conway Papers (Oxford University Press, 2014) and, edited with Joshua Eckhardt, Manuscript Miscellanies in Early Modern England (Ashgate, 2014), and he is General Editor of the OUP edition of the Correspondence of John Donne. 



























An Unlocking History Research Group team member holds a rare unopened example of a letterpacket with a paper lock. This locking mechanism was used since the 1500s, but until now, we’ve only ever seen examples opened and “unlocked” in archival collections. Virtual unfolding algorithms helped to determine that the packet was locked using a low security technique without tearing open the letter. 

Technical details: Category 15L. Letterpacket dimensions: H55mm x W90mm. Format: 4RW

Computer-generated unfolding sequence of sealed letter DB-1538. In our paper we describe how “virtual unfolding” was used to read the contents of sealed letterpackets from 17th-century Europe without physically opening them.

Courtesy of the Unlocking History Research Group archive.

The letters are from the Brienne Collection, Sound and Vision The Hague, The Netherlands. 


This event is run in partnership with The Warburg Institute.