Jana Dambrogio and Daniel Starza Smith introduce you to letterlocking. Filmed in 2019 by the Darek Bok Center for Teaching and Learning, Harvard University. Directed by: Emilie Hardman. Edited by: Jordi Rocha. Accessibility documents for this video can be found at https://dataverse.harvard.edu/dataverse/whatisletterlocking
What is letterlocking?
Letterlocking is a modern term used to refer to the ways people in the past built security into their letters. Before the invention of envelopes, the letters themselves had to be folded or rolled up and secured shut for sending, to avoid prying eyes. Thousands of innovative techniques were developed over hundreds of years. Letterlocking relates to other kinds of information security techniques used by humans to protect their communications – just as you might now be concerned about people hacking into your email, people have tried to secure their letters shut for hundreds of years.
We’re only just beginning to understand letterlocking, to map out the evidence we need to interpret it, and to develop a language to talk about it. The study of letterlocking (the historical phenomenon) is also called letterlocking – so if you’re watching our videos and making our models, you’re also a letterlocker. Congratulations! You’re continuing an extremely important historical tradition.
In the Dictionary of Letterlocking, we define letterlocking in three ways:
1. The act of folding and securing an epistolary writing substrate (such as papyrus, parchment, or paper) to function as its envelope or sending device. As distinct from the use of a wrapper or gummed envelope, and from paper-folding traditions such as origami.
2. A sub-category of a 10,000-year document security tradition, pertaining to epistolary materials.
3. The discipline which studies the materially engineered security and privacy of letters, both as a technology and a historically evolving tradition.
How do I cite letterlocking research?
DoLL
Cite as Jana Dambrogio, Daniel Starza Smith, and the Unlocking History Research Team. 2016–. Dictionary of Letterlocking (DoLL). Categories. Last updated: 26 July 2024. Date accessed: [Date]. Abbreviated on this page: (DoLL 2024). All images except when noted are courtesy of the Unlocking History Research Group archive, MC0760, MIT Libraries.
Instructional Videos
Citation information:
Authors: Jana Dambrogio, Daniel Starza Smith and the Unlocking History Research Group.
Video Title (Date of letter)." Letterlocking Instructional Videos. Unlocking History number ####/Letterlocking Unique Video number: ###. Date filmed: Month Day, Year. Duration: Minutes:Seconds. Date posted: Month, Day, Year. Video URL: [Insert URL]. Date accessed: [Date].
How is letterlocking different than sending a postcard or sending a letter in an envelope?
Locked letters are a really fun way to send a letter. Have you ever received a postcard? Or a letter in an envelope? Well, locked letters are a hybrid technique between both. A locked letter is similar to a postcard in that it is made from a single sheet of paper but different in that it is folded to become its own envelope. So it provides privacy found in letters sent in envelopes without actually needing an envelope. Instead the letter itself can play both roles. Depending on how you fold the sheet of paper (and there are many ways to lock letters shut!), you may not even need tape, stickers, sealing wax, or glue to seal them shut. Sometimes folding and tucking actions are all that is needed.
Maybe you were a letterlocker and you didn’t even realize it. Did you ever write a note to your friend and fold it up to pass in class, undetected? Did you ever fold up a sheet of paper with a note on it into a triangle to flick across a room? These are kinds of letterlocking.
How do I learn how to letterlock?
Alongside this website, we’re building a series of free tools so that you can teach yourself this important historical practice. The first place to start is the YouTube and Vimeo channels, where you can find lots of instructional videos. In due course, we’ll be releasing step-by-step diagrams and pre-printed sheets with folding instructions on them.
Members of the Unlocking History team run hands-on workshops at schools, universities, museums, archives, libraries, and other research institutions. We will keep this website updated with upcoming workshops.
Is letterlocking like origami?
Letterlocking shares similarities with origami, but also has some important differences. The Japanese origami tradition literally translates to paper folding, and is one of many paper-folding traditions around the world, including jong-i-jeobgi (Korea), papiroflexia (Spain), pop-up books, note-passing, and napkin folding. Letterlocking is different in that it combines the study of epistolary paper folding with the study of the physical security and privacy built into letters.
Do you know about the seventeenth-century trunk filled with 2,600 undelivered locked letters?
Yes! The Brienne Collection has been a vital source for the study of letterlocking, because it contains so many unopened letters (approximately 600). In fact, Jana and Daniel from Unlocking History are also part of Signed, Sealed, and Undelivered along with Rebekah Ahrendt, Nadine Akkerman, and David van der Linden.
For more on that project, check out the pages and some of our press coverage.
What is information security?
We define information security as: “The practice of defending information from unwanted inspection, modification, recording, transmission, destruction, or other intervention. Information security encompasses document security, but also takes into account non-tangible communication methods, such as whispering or email encryption.”
Letterlocking is a form of information security – specifically, it is “document security.” Letterlockers used a variety of techniques to ensure that their information was protected from prying eyes as the letter made its way from writer to recipient. While some locked letters can be opened and reclosed without evidence, some locked letters may be tamper-evident or even tamper-proof. Spies might think twice before attempting to read the latter!
What is conservation?
The American Institute for Conservation defines it as “The profession devoted to the preservation of cultural property for the future. Conservation activities include examination, documentation, treatment, and preventive care, supported by research and education.” Letterlocking sprang from discoveries made by Jana Dambrogio while she was pursuing a conservation fellowship in the Vatican Apostolic Archives, between 2000 and 2001. The study of letterlocking is rooted in the conservation philosophy that artifacts should be cared for with as little intervention as possible. Though conservation is often associated with “repair,” letterlocking serves as a reminder that holes and tears in a substrate may have been placed intentionally, and should be studied and preserved as they are found.
What does Creative Commons Attribution–NonCommercial mean?
All letterlocking materials, unless otherwise stated, are under a Creative Commons Attribution–NonCommercial 4.0 International (CC BY-NC 4.0) License, including printed materials, workshop materials, and digital materials (videos, pictures, social media posts, and website information).This license allows you to both share and adapt any of the letterlocking materials as you wish.
However, you must provide proper attribution, which requires:
1.) crediting the Unlocking History team;
2.) providing a link to the letterlocking materials used;
3.) indicating if any changes were made to the letterlocking materials.
Citation information has been provided for most letterlocking materials. In addition, you may only share and/or adapt these letterlocking materials for NonCommercial purposes.
If you want to use letterlocking materials for profit, you need to contact the Unlocking History group to obtain a licensing agreement and agree to share any profits.
Please see the Creative Commons website for a summary and for the license legal code. Please contact the MIT Technology Licensing Office for any other licensing inquiries.
What is the Unlocking History Research Group?
Unlocking History was set up to coordinate multiple related projects, including letterlocking research, conservation, workshops, and literary and historical research into letters. Run between MIT Libraries and King’s College London, Unlocking History brings together a wide range of expertise, from tool-making to graphic design and editorial skills.
Unlocking History members include staff, students, and interns at MIT Libraries’ Wunsch Conservation Laboratory, museum curators, and King’s College London undergraduate research fellows (KURFs). Jana Dambrogio and Daniel Starza Smith are the co-directors of Unlocking History.
We also work closely with collaborators across the humanities, sciences, the library and archive sector, and the cultural sector. Our collaborators include the archival scholars on the Signed, Sealed, and Undelivered team, mathematicians working on unfolding algorithms, and physicists developing new x-ray scanning technology.
To meet the Unlocking History team-members and collaborators, see our team page: http://letterlocking.org/team.
How does the Unlocking History group incorporate equity, diversity, inclusion, and social justice in its research?
The Unlocking History research group is committed to promoting equity, diversity, inclusion, and social justice. Letterlocking practices crossed the world over many hundreds of years, and letterlocking was used by people from an enormous range of backgrounds and cultures. We seek to tell a truly global story. In 2020, we established an internal fund to support research into equitable research and teaching practices, so that we can continue to build them into the heart of the project.
Is letterlocking really so secure? Surely it’s quite easy to break into a letter, no matter how elaborately it’s been secured?
This is an important question. Paper is relatively easy to tear, after all, and wax seals and thread ties can be cut with a knife. Letters are of course designed to be opened – but only by the intended recipient. Some of the techniques we describe are about creating barriers to entry, but many are designed to show evidence of tampering, to at least make an interceptor think twice.
It might seem strange to us today that people put so much effort into designing complex security techniques and building them into their letters. This is precisely what we want to find out more about by studying the evidence closely. What did people think they were doing when they were letterlocking? How did they learn it, and what kinds of decisions did they make when choosing between different methods?
We are also interested in the kinds of social signals sent by different kinds of letterlocking. Issues of affection, respect, courtesy, and rank could be embodied in the ‘materiality,’ the physical materials chosen to make the letter (quality of paper or color sealing wax) – the effort that went into writing it and forming it into a packet.
Who letterlocked?
Everyone!
The letterlockers you will encounter in our research include some of the most well-known individuals from history – Dutch philosopher Desiderius Erasmus (1466–1536), Elizabeth I Queen of England (1533–1603) and her spymaster Sir Francis Walsingham, poet and preacher John Donne, Mary Stuart, Queen of Scots (1542–1587), Marie Antoinette, Queen of France (1755–1793), and Mahmud ibn Muhammad, Bey of Tunis (1757–1824). Thanks to their fame, these individuals’ letters have been carefully archived and preserved, making them ideal to study. But we also want to stress that letterlocking was used by “ordinary” people: merchants, lovers, soldiers, musicians; people of any gender, religion, of socio-economic background. So we include letters from the obscure Venetian Tomaso di Levrieri and soldiers on the front lines of both World Wars. All the individuals we examine, whether they were writing in the thirteenth century or are alive today, folded their writing substrate and secured it shut to function as its own envelope. Recognizing the fundamental role that letterlocking played in centuries of correspondence is important in itself, but we want to go further and show just how varied, fashionable, clever, and witty letterlockers have been throughout history.
What do I need to start letterlocking?
If you’re just starting out, you really can use any paper lying around the house to make some basic models (see here for simple models that do not require adhesive). Standard printer paper works just fine. Depending on the models you want to make, a pair of scissors and some thin sewing thread or embroidery floss can also be useful. Some models are wrapped around with thread and tied up; others are actually sewn through, which will require a needle. You could use a little glue, some stickers, or a postage stamp as adhesive in place of sealing wax.
Some materials are not suitable/safe for children, or require adult supervision. Please see the separate FAQ on this topic: “Is letterlocking suitable for children?”
The next step is investing in some sealing wax and a seal-stamp. Of course, adding the adhesive is all part of the fun! In our experience, having run dozens of workshops over the years, the easiest method is to get a low-temperature glue gun which takes sticks of glue-gun sealing wax. What it lacks in historical authenticity it makes up for in ease of use, especially if you are going to make multiple models. Please note: if you do use sealing wax sticks, the glue gun will retain residue from the wax.
Real sealing wax made of shellac leaves a beautiful impression, but it is a bit harder to work with. It has to be melted over a naked flame, and it solidifies quickly into a brittle substance, meaning that you have to lock quickly and confidently. Practice makes perfect, though, so it is worth having a go. Give it a try!
Finally, if you want to have a go at making models that look, feel, and sound more like historic letters, you may need to invest in some more advanced materials, including hand-made paper. Hand-made paper is strong, so it folds beautifully; and it’s thin, so it’s easy to make a seal impression on it or through it. It comes in a variety of sizes and has cool features like deckle edges and chain lines.
As well as learning about letterlocking, you can use our resources to learn about other aspects of historic letter-writing processes. These include making your own ink or even your own invisible ink! Naturally, these activities involve quite specialist materials, but we think they are worth it for the results.
For a full list of the Tools and Materials of letterlocking, see our ‘Tools and Materials’ page.
Where can I find the tools and materials you use in your videos and workshops?
Please see our Tools and Materials page. We do not have any commercial arrangements with any of these suppliers, and our mention of them is not a guarantee that their products will work for you. However, we have purchased materials from them in the past and found them useful. We encourage you to support your local craft supply stores and independent retailers.
What do conservators do?
Conservators are trained to care for cultural heritage materials according to a code of ethics, such as the one put forth by The American Institute for Conservation. They provide storage and handling that protects collections from the elements so that they can be studied for years to come. Many conservators specialize in dealing with a type of material, such as books or painting. Much of the work done on letterlocking currently happens in the Wunsch Conservation Laboratory at MIT. The mission of the Wunsch Lab is to “preserve information, protect and promote the conservation of MIT’s tangible collections through thoughtful collaboration, innovation, research, and discovery to inspire and engage.”
Most historical examples of locked letters are made of paper. Traditionally, paper conservators have been tasked with treating historical paper materials, which could include surface cleaning, flattening, and repairing holes and tears with adhesives and tissue. But surface dirt, crease patterns, and holes and tears in paper have told us so much about the history of letterlocking, inspiring conservators to take a non-interventive approach to caring for historical models.
Why do we want to conserve the folds?
Folds are critical to understanding how a letter was once created and sent as a letterpacket. If the folds are flattened out, we can no longer reconstruct how a letter once locked.
What is paleography?
Paleography (or palaeography in British English spelling) refers to the study of any type of handwriting, including when people print (not connecting each letter in a word) or write in cursive (connecting each letter to each other in a word).
Why would an individual use more than one letterlocking format to send their letters?
This is one of the first questions we began asking from the beginning of our research because in our research we find often that the same person used more than one letterlocking technique, some building in higher security than others. Why? The questions we are asking include. For example, we’ve documented at least eight different locking techniques used on letters signed by Queen Elizabeth I of England. Did she execute the locking steps on her letters? Did she choose a letterlocking technique because she enjoys using one locking technique more than another? Or out of habit? Or because one provided more tamper-evident features that another? These are the questions we hope to answer and one of the main reasons we are creating resources to help others learn and adopt letterlocking so that they too can begin to answer these questions in their own research.
When was the invention of the gummed envelope?
In the Dictionary of Letterlocking (DoLL), the Unlocking History team defines envelope as “a pre-made flat container for a letter or document that dictates the size of the contents inside.” As such, envelopes are distinguished from wrappers, which are custom made to fit contents.
The envelope as we define - a pre-folded, mass-produced, and standardized size container - was developed in an effort to standardize postal sizes and prices. The first envelopes were developed in 1845 with the invention of Edwin Hill and Warren de la Rues’ steam-powered folding machine. This process was automated with Russel Hawes, an American envelope maker, in 1853. The invention of the gummed envelope - an envelope with adhesive pre-added to the paper - shortly followed in 1876, thanks to James Green Arnold’s machinery.
Envelopes quickly superseded the practice of letterlocking or of using wrappers; since early envelopes were paid based on their standard size, it was advantageous to fit contents into the smallest possible envelope for the cheapest price rather than to create a custom packet that may cost more.
How is letterlocking connected to cybersecurity?
Cybersecurity is a part of information security and has developed in an effort to protect against unauthorized use of electronic or digital data. In the digital age, most people opt to send electronic letters rather than physical. However, the concerns of privacy and security during information transmission are unchanged; a variety of protection methods can be mapped to letter-writing or letterlocking techniques.
Just as people today may use cryptography to obscure their email message, historic letter writers also employed code to protect their information. People in the past also had the option to filter out spam mail and would refuse letters if they did not recognize the handwriting, seal, or even locking style. Of course, just as email addresses and usernames can be stolen or “spoofed,” so can the historic authentication methods listed.
Similar to the philosophy of anti-malware programs and end-to-end encryption, historic writers also created cross-hatching in the margins or any blank space on the page so as to leave no space for someone to write an additional message.
The folding and securing of letters most closely resembles modern-day digital intrusion detection or anti-spyware software. Historic letterlockers might have employed a lock which needs to be broken to access the content inside. If the letter had been opened previous to the intended recipient, the lock would have acted as a tamper-evident device. Moreover, a letterlocker could write across a lock or use a lock made from the same sheet of paper as the letter in order to show if the lock had been tampered with and replaced in transit.
Akin to a firewall, letterlockers may have employed a particularly complicated lock or letter folding pattern, cautioning a potential spy away from attempting to break in. Conversely, decoy locks or packets - letters with harmless or unimportant content that look from the outside to be very well secured - would confuse would-be spies looking for critical information, similar to modern deception technology heading off would-be hackers.