The towers of the NH Hotel Fiera in Milan are located a short distance from the Rho-Pero exhibition center, opposite the main entrance. The flagship expression of the creative verve of Dominique Perrault, an internationally renowned French architect, are two gigantic monoliths with a sober and controlled geometry of shiny black color, inclined 5 degrees from the vertical, which host 400 rooms classified as four stars. Perrault's minimalist vocation is best expressed in the refined treatment of the external skin of the buildings, made up entirely of ventilated walls perforated by irregular holes that underline its homogeneity but also its subtle tension. The elements that make up the facing, completely with hidden anchorage, arise from the happy collaboration between the designer and Marazzi Engineering, which on request supplied a special product, perfectly in keeping with the stylistic canons of the French architect and his continuous aptitude for experimenting with materials and their evocative power. The result is Jolly Black, a large format slab (50 x 100 cm) made up of a base of porcelain stoneware covered with a layer of black glass ceramic.