The term Guilloche refers to a type of decorative engraving, that produces a fine mesh of arcs and waves. This technique was commonly used throughout the late 19th and early 20th century to decorate many shop produced goods by using a geometric lathe. No longer in vogue today it is still encountered on banknotes and official documents. For these the Guilloche is employed as a security measure to make counterfeiting difficult. To be accurate the metal plate originally used to print these items is engraved with a guilloche. The printed image may be more correctly described as overlapping Spirographs or Hypotrochoids.
The image above was created by Aegir Hallmundur. If you want to see more of the fantastic work that inspired this article or try your hand at digital Guilloches check out his article. Ministry of Type’s take on Guilloches