A mosaic had already been restored in the Roman villa of Balacapustza in Hungary. In this volume, however, the author relates the technical problems which he faced in the course of this work: removal and cleaning of the recent discovery, detaching of the first mosaic from the concrete bed into which it had been set and remounting of the two mosaics on the same polyurethane foam support. He emphasizes the need to properly clean the surface so as to remove the porous deposit which forms after too frequent washings. This deposit makes colors dull.