The relief is a form of transition between full relief sculpture and painting. In fact with the latter, it shares the perspective and the light-shade effect, being closer to the contour moulding and to the effective chiaroscuro performance rather than to floors graduation line, typical of the real sculpture.
During the Italian Renaissance, the relief  reaches its maximum development through the works of Andrea Pisano, Donatello and Della Robbia, whilst in the Baroque period, it takes a precise role in the plastic decoration and in the applied arts.  The neoclassicism produces reliefs of great beauty thanks to Thorwaldesen and Canova, whilst the twentieth century sees committed to this field, artists like Rodin and many Italian ones like Medardo Rosso, Manzù e Minguzzi.
Even with the due fine distinctions, in this collection we find examples of continuity in this particular field and therefore, besides the traditional full relief representation, Principe presents interesting cues of porcelain bas-, mid- and high-relief in porcelain as a form of ornamental surface emerging from the painted bottom.