What's the difference between i.e. and e.g.?
type of mosaic work frequently used in Hellenistic and Roman times, in which part or all of a figural mosaic is made up of small, closely set tesserae (cubes of stone, ceramic, glass, or other hard material) that permit fine gradations of colour and an exact following of figure contours and outlines. The word vermiculatum ("wormlike") refers to the undulating rows of tesserae that characterize this work. Opus vermiculatum was generally used for emblemata, or central figural panels, which were surrounded by geometrical or floral designs in opus tessellatum, a coarser mosaic technique with larger tesserae; occasionally opus vermiculatum was used only for faces and other details in an opus tessellatum mosaic