Vermiculation

Vermiculation naturally occurs in patterns on a wide variety of species, for example in the feathers of certain birds, for which it may provide either camouflage[1] or decoration.

It also appears in architecture as a form of rustication where the stone is cut with a pattern of wandering lines.

In metalwork, vermiculation is used to form a type of background found in Romanesque enamels, especially on chasse reliquary caskets.

In this case the term is used for what is in fact a dense pattern of regular ornament using plant forms and tendrils.

In Ancient Roman mosaics, opus vermiculatum was the most detailed technique, and pieces are often described as "vermiculated" in English.

Close view of a common teal showing the vermiculation pattern in its feathers.
Detail showing a "vermiculated" background on a chasse reliquary casket
Architectural vermiculation in Paris