The reliefs form part of the sculpture group of works.
The first relief is created in 1952; after 1957 this area of activity becomes more and more significant.
The structured surfaces consist of plaster or synthetic resin, then mostly of aluminium. The term "light relief" is one coined for the first time by Heinz Mack.
The articulation of the light on the relief area, the capacity for reflection, the immaterial appearance: all these things carry great significance for the artist.
During his artistic expeditions in the Sahara, he also created sand reliefs within the natural area of the desert, which were documented in photographs and on film.
After these travels the so-called "sand reliefs" were created in the artist's studio, from the sand brought home.
Mack's intention of making light, structure and movement visible becomes evident in the reliefs.