'Opus signinum' is an antique floor-covering technique, especially noted in the Mediterranean area. The technique is based on a waterproof mortar of a mixture of lime, water and tile powder which gives it a reddish colour. This current research focused mainly on the opus signinum process as recorded in the antique literature (especially Vitrivius and Pliny) and then scientific analysis, in order to define the composition of the mortar. Over 100 pavements from Mediterranean countries (5th c BC - 2nd c AD) have been compiled in the catalogue, making it possible to study the ornamental patterns and the various uses the rooms/spaces were put to.