The encyclopedic Das Leben, published in five volumes over the span of a decade, included over 1600 pages, more than 1200 illustrations, and would be Kahn’s opus. It was during this project that Khan perfected his modernist style of visualization, particularly his analogies of biology to industrial and mechanical processes – Man as Industrial Palace. It was a technique that would be heavily imitated over the next century.

Kahn, using publisher Kosmos’ stable of illustrators, drew on nearly every contemporary style, including Neue Sachlichkeit, Dada, Surrealism, even Constructivist photomontage. His avant-garde visualizations were highly influential with Weimar-era designers, including Herbert Bayer and Walter Gropius of the Bauhaus.