The Spiral-Locked Letters ofElizabeth I and Mary, Queen of ScotsDecember 12, 2021https://www.bl.uk/eblj/2021articles/pdf/ebljarticle112021.pdf Mary, Queen of Scots, sealed her final missive with an intricate spiral letterlock https://arstechnica.com/science/2021/12/mary-queen-of-scots-sealed-her-final-missive-with-an-intricate-spiral-letterlock/