'Opus sectile' is a special kind of wall and floor decoration. Of ancient origin, it enjoyed wide diffusion in Roman and Early Christian art until the 7th century. In this technique pieces of marble (or other materials) in various colours were cut into fine geometric and floral shapes, or even figures of humans and animals, and inlaid against a different-coloured background to create diverse compositions.
Wherever used, this kind of decoration, combined with polychrome dado (marble panelling), endowed the churches with special splendour. The loveliest example of 'opus sectile' walling in Greece survived until 1917 in the basilica of Ayios Demetrios in Thessalonike. The technique of 'opus sectile' was also used in other churches of the city, as well as in monuments at Philippi.