Abstract: Allows tesseras to be obtained with optimal results in the creation of a mosaic. A terracota support is realised of an optimal size of 100×100 mm and a thickness of between 1.5 and 3 mm, subject to allowances for working, also by a craftsman, The support 1 made to allowances for working, also by a craftsman The support 1 made out of clay, before firing is scored or moulded on the rear part with grooves which are regular, parallel and perpendicular or oblique, at a distance of betwen 5 and 10 mm (or other, according to requirements) with a depth of between about 0.75 and 1.5 mm. After the first kil firing, one then proceeds to the kiln glazing of the front part 2. The grooves 3 allow an easy and regular breaking of the glazed tile. With its breaking the tesseras are obtained, with perfect edges and the rear part no visible, thanks particular to the reduced thichness. This then allows an easy resizing with side-cutting nippers of the tessera and the adaptation thereof to the design.