Karl Duschek’s free art works in ‘System and Series’ form a substantial antipole to his internationally renowned creations as a graphic designer. The five most important work phases of his free art are retrospectively presented in a five-part work commissioned by the Daimler Art Collection in 2007, Vier Stufen Silbergrau [Four levels silver grey] being part of this series. Placed in the tradition of constructive concrete art, space and emptiness – as well as the use of the primary colors yellow, red and blue and the secondary color green – form the visual tools for a systematically conceived series of work. The standard format 90 × 90 cm has been uniformly applied, and Duschek started working on the commission chronologically with black. White and silver, and horizontal vertical-diagonal works. The group Pinselspitzen (brush points) is based on the principle of chance, as used in Japanese calligraphy, applied with an approximately two-meter long brush on canvas. Eight vertical, systematically transferred wooden squares represent the series of installations, which were followed by roughly four years of work with kinetic light.