{{Short description|Engraving device}}{{More citations needed|date=March 2026}}thumb|right|Banknote motif created with a geometric lathe
A '''geometric lathe''' was used for making ornamental patterns on the plates used in printing bank notes and postage stamps.<ref>{{Cite web |title=Geometric Lathe, Philadelphia, United States, ca. 1925 |url=https://americanhistory.si.edu/collections/object/nmah_1424363 |access-date=2026-03-19 |website=National Museum of American History |language=en}}</ref> It is sometimes called a guilloché lathe.
==History== It was developed early in the nineteenth century when efforts were introduced to combat forgery, and is an adaptation of an ornamental turning lathe.
The lathe was able to generate intersecting and interlacing patterns of fine lines in various shapes, which were almost impossible to forge by hand-engraving. They were used by many national mints.
==See also== * Rose engine * Security printing * Guilloché * Spirograph * Tusi couple
== References == {{Reflist}}
==Further reading== * Peter Bower, 'Economic warfare: Banknote Forgery as a deliberate weapon', and Maureen Greenland, 'Compound plate printing and nineteenth-century bank notes, in Virginia Hewitt, ed. ''The Banker's Art: Studies in paper money'', pp 46–63, and pp 84–87, The British Museum Press, 1995, ({{ISBN|0-7141-0879-0}})
==External links== *[https://collection.sciencemuseumgroup.org.uk/objects/co60751/geometric-chuck-19th-century Geometric chuck, 19th century, Science Museum Group Collection Online]
Category:Automatic lathes Category:Money forgery
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