The surface of a sculpture is smooth or rutted, inviting or dismissing. What is hidden beneath the surface and how its meaning has changed from the early 20th century to today is demonstrated by important works by, among others, Auguste Rodin and Medardo Rosso, as well as by contemporary installations by artists such as Rebecca Horn, Carsten Nicolai, Janet Cardiff and George Bures Miller. An enlightening theme, especially in view of the omnipresence of surfaces of digital devices.