A particularly important point is the selection of the appropriate tile format. The basic principle is: the smaller the room, the larger the tiles. In addition to the effect of the optical room enlargement, the use of large tiles results in a calmer joint pattern. Likewise one should do without partial tiling with small areas and always tile up to the room ceiling, in order to avoid additional interruptions by plaster or wallpaper. Furthermore, the laying of rectangular tiles instead of square tiles is recommended for small bathrooms. Tiles laid in landscape format make rooms optically wider. Tiles laid on edge raise the ceiling optically.