The six splendid doors in mahogany and walnut of the Sala Nera (“Black Room”) were designed by Bertini, modelled in stucco by Barzaghi and made by Speluzzi and Zaneletti. In the middle of the doors, on the inner side, there are carvings in high relief of allegorical figures of the Four Seasons and of Day and Night.
The exterior side is covered with Morocco leather with impressions in gold. It is a very fine piece of workmanship, combining different materials in an elegant harmony characteristic of the taste of the period.