Palazzo Massimo alle Terme in Rome | Opus vermiculatum is a method of laying mosaic tesserae to emphasise an outline around a subject. This can be of one or more rows and may also provide background contrast, eg as a shadow, sometimes with Opus tessellatum. The outline created is often light and offset by a dark background for greater contrast. The name opus vermiculatum literally means "worm-like work", and has been described as one of the most demanding and elaborate forms of mosaic work.
A dog and a knocked-over gold vessel. Greco-Roman Museum, Alexandria, approx. 200-100 BC. The scene formed the center piece of a large mosaic floor. This period represents a high point in the mosaic craft in antiquity. Many of the tesserae (the little pieces of stone/glass) are only 1-2, mm across, which allows the mosaicist to achieve a painting-like effect. This technique was known in antiquity as opus vermiculatum, or ‘wormy work’.
opus vermiculatum---taken from the latin word 'worm.' It refers to lines of tesserae that snake around a feature in the mosaic. Often 2-3 rows of opus vermiculatum appear like a halo around something in a mosaic picture, helping it stand out from the background.
-2eS, Pompéi, Maison du Faune, Salle 34 Triclinium 1er STYLE Opus Vermiculatum: EROS ailé avec emblèmes dionysiaques chevauchant un Lion. Emblèmes: Âge d'or (coupe) + Bonheur dionysiaque (vin). Tradition grecque de célébration du Banquet
La Battaglia di Alessandro e Dario. Mosaico in opus vermiculatum, tessere policrome. 100 a.C., dalla Casa del Fauno, Pompei. Forse copia di un affresco di Filosseno di Eretria. Museo Archeologico Nazionale di Napoli.