Caroline Dugué : The bichrome sectilia pavimenta of Roman Gaul or luxury in black and white. The pavements called sectilia pavimenta in Antiquity appear in Italy in the last decades of the 2d century B-C. or the first ones of the following century. Those floor decorations are made of thin slabs of marble or polished stones called crustae which are sawn and cut, and then imbricated together so as to form geometrical patterns obtained by chromatic contrasts. These stone patchworks spread in Italy, then, little by little, to all the areas of the Roman Empire. In Gaul, bichrome formulas, founded on the use of black and white, exclusively used marble or lime stone associated to schist or slate. The black and white sectilia are obeyed to the orders of patrons, whether aesthetic, functional or financial.