Guilloche

Here's something I learned today: a new word, though it applies to something we used to see all the time, in the days when we still handled currency—guilloche. I ran across it in a proofreading job, a reprint of Occidental Mythology by Joseph Campbell. The sentence: "A goddess follows in the role of the mystic mother of rebirth, and below is a guilloche—a labyrinthine device that in this art corresponds to the caduceus." (I had rather hoped that this job would be a bit more lively, but Campbell was a ponderous writer.)

I found two definitions for guilloche, or guilloché (etymology unknown: possibly named for a carving tool devised by a French engineer named Guillot). First: "architectural ornamentation resembling braided or interlaced ribbons." As in this example from Assyria, 9th century B.C.:

Or this, from a more recent skyscraper in Chicago:

But guilloché is familiar to anyone who has studied a dollar bill

or taken a close look at a high-end watch face 

In the latter case, it's simply decorative; in the former, it serves security purposes.

According to Wikipedia, guilloche "is a decorative technique in which a very precise, intricate and repetitive pattern is mechanically engraved into an underlying material via engine turning, which uses a machine of the same name, also called a rose engine lathe."

I found a gentleman named Ben Hodosi online who offers up contemporary guilloche designs as "security graphics."

Here are a few more examples:

 

Guilloche: the serious answer to the spirograph.