Unlocking History number (UH#)
UH0224
Original
Catherine de’ Medici’s concealed spiral-locked letter to Raimond de Beccarie, Monsieur de Fourquevaux (1570). MIT Libraries, DC111.A2 C38 1570.
Model and research notes
MIT Libraries, Unlocking History Research Group archive, MC0760, Box 29.
Letterlocking Unique Video number(s) (LUV #s) & Instructional video(s) URL
LUV224 https://youtu.be/U3lGlmRPMKw
Instructional video info transcription
UH0224 video info transcription alt text 7:42 mins
Letterlocking Category number (LC #)
LC31H
Letterlocking Format number (LF #)
4RXW
Security score
High
Assessment of confidence in assigning LC#
Attested
Substrate
Paper
Dimensions
Opened (in mm): H: 305mm x W: 203mm
Letterpacket (in mm): H: 40mm x W: 101.6mm
Lock: Short dagger H: 72 mm x W: 13 mm at widest point
Manifestation
Opened
Distinctive letterlocking style(s)
Spiral lock
Locking mechanism
Lock
Security enhancements
Authenticated covered seal
Authentication
Matching lock with paper from which it was cut
Letterlocking category formula (shorthand)
LC31H
Fold + Slit/Hole + Adhere + Lock-SA
(F + S/H + A + LSA)
Letterlocking manipulation sequence (shorthand)
Fold + fold + fold + fold + fold + fold + fold + slit + slit + slit + lock-SA + lock-O + lock-O + adhere + adhere
Locking instructions
Orient your A4 paper portrait (short edges at head and tail edges)
Edge fold. Fold the top of the left long edge inwards about one finger width wide
Internally slice lock SA. Keeping this edge folded over on itself, slice out a triangle-shaped strip of the substrate
Unfold. A thin dagger-shaped strip of the substrate protrudes and attached
Fold short edge to short-edge with the lock left protruding. Keep folded.
Fold the bottom edge up. Keep folded.
Flip the substrate over.
Gatefold long-edge to long-edge towards each other in the center. Keep folded.
Fold long-edge to long-edge while the lock protrudes. Keep folded.
Fold to substrate short-edge to short-edge to form letterpacket – all the time with the lock protruding. Keep folded.
Slit with bradawl. Following an imaginary line down from the center of this fold, us a bradawl to make a 3mm slit in the packet close to the accessible edge.
Fold the single layer of paper in half along its vertical axis.
Lace the tip of the lock through the slit in the packet.
Flip the packet over.
Slit with bradawl passing through the whole packet and the lock on the other side.
Lace the tip of the slit.
Flatten the body of the lock to lie flush with the packet.
Flip the packet over.
Slit with bradawl through both the packet and the lock so that the lock tip can pass through the packet a final time in a spiral motion, until the tip is left protruding
Apply warm sealing wax adhesive over the tip.
Apply a square-shaped paper lock-O over the sealing wax to create a covered seal
Impress the seal stamp into the warm sealing wax through the paper to authenticate.
Flip the packet over.
Apply warm sealing wax adhesive over the self-stabbed lock and the panel.
Add a diamond-shaped paper lock-O over the sealing wax to create a covered seal.
Impress the seal stamp into the warm sealing wax through the paper to authenticate.
Flip over the letterpacket
Write address on the outer panel.
Images
Images from our Spiral lock article
Overlay Key
Images: View: key to overlay
Images: Download: key to overlay
Images: View: drawing of opened letter, recto/verso
Images: Download: drawing of opened letter, recto/verso
Recto/Verso
Images: View: address side and reverse side
Images: Download: address side and reverse side
Locking Mechanism
Images: View: detail of letterpacket
Images: Download: detail of letterpacket
Images: View: details of penguin head lock
Images: Download: details of penguin head lock
Locking Mechanism – letterpacket with overlay
Images: View: Locking mechanism of letterpacket
Images: Download: Locking mechanism of letterpacket
Locking Mechanism – open letter with overlay
Images: View: detail of locking mechanism overlay
Images: Download: detail of locking mechanism overlay
Images: View: details of locking mechanism
Images: Download: details of locking mechanism
Covered authenticated seals
Images: View: details of authenticated covered seal
Images: Download: details of authenticated covered seal
Images: View: detail of authenticated covered seal, raking light
Images: Download: detail of authenticated covered seal, raking light
Lock remnants
Images: View: details of lock remnants
Images: Download: details of lock remnants
Images: View: details of lock remnants
Images: Download: details of lock remnants
Foldable(s)
Forthcoming
Step-by-steps
Forthcoming
Substrate map
Forthcoming
Virtual unfolding results
NA
Manipulations
Writing: Margin folds, Mourning Stationery
Postal: NA
Opening: Tears
Filing (Storage, Display): NA
Repair: NA
Damage
Tears
Ink Corrosion
Features
Dirt on panels/ in crease
Radiating wrinkles
Wrinkles
Signed holograph letter
Slits: 5–6 mm, pen knife stab?, 3 slits per panel
Lock tip points down to edge
Transcription and translation
Forthcoming
Context
Forthcoming
Article(s)
2023. Daniel Starza Smith & Jana Dambrogio. Letterlocking: securing correspondence before envelopes in Routledge Encyclopedia of the Renaissance World. Lauren Shohet, subject editor.
2021. Jana Dambrogio, Daniel Starza Smith, Jennifer Pellecchia, Alison Wiggins, Andrea Clarke, & Alan Bryson. Illustrations by Nicole Araya, Annie Dunn, Matthew Li, & Jana Dambrogio. The Spiral-Locked Letters of Elizabeth I & Mary, Queen of Scots (accessible PDF). Electronic British Library Journal, 2021, Article 10. Open Access Downloads as of August 2022: 18,000 (British Library: 17,500; MIT DSpace: 590)
Book
Jana Dambrogio and Daniel Starza Smith with the Unlocking History Research Group. Letterlocking: The Hidden History of the Letter. Cambridge and London: MIT Press, 2025.
Further resources
Dataverse resources for spiral lock: https://dataverse.harvard.edu/dataverse/spirallock
Citation for the letter(s)
UH0224
Original
Catherine de’ Medici to Raimond de Beccarie, Monsieur de Fourquevaux (1570). MIT Libraries, DC111.A2 C38 1570.
Model
MIT Libraries, Unlocking History Research Group archive, MC0760, Box 29.
Video
Jana Dambrogio, Daniel Starza Smith, and the Unlocking History Research Group. Title: "Catherine de’ Medici’s concealed spiral-locked letter to Raimond de Beccarie (c.1570)," Letterlocking Instructional Videos. Unlocking History number 0224/Letterlocking Unique Video number:224. Filmed: 30 July 2021. Duration: 7:51. Posted: December 10, 2021. URL: https://youtu.be/U3lGlmRPMKw. Accessed: April 14, 2025.