Heinz Rasch in: Willi Baumeister 1859-1955, Art and Museum Society, Wuppertal, 1959.
“(…) Thus in 1938 Baumeister discovered the flying forms painted 20 years earlier by the Russian Malevitch. His figures become tropical and kidney-shaped ideograms. And this is the beginning of his second period, that of mature virtuosity, in which Baumeister found his independence, his unique and unmistakable style of painting. The great and decisive change coincides with the beginning of his almost 7 years of activity in Wuppertal. (…)

Secluded from the art production of the environment, also abroad, Baumeister’s completely own and independently inspired works now emerge here. At the beginning there are the pictures Urpflanzenreich and Urtierreich. The rock drawings of the Stone Age provide further inspiration. (…) The art of primitive cultures is added. Then follow early Babylonian, Egyptian and Greek Archaic elements and East Asian influences. In addition, there is the study of fabric formation and modulation.(…)

These pictures of his second great and last period are, just like the pictures of the first period, an immediate statement about their time. When the war was over and our gaze could once again wander across the borders, we saw that Baumeister, without knowing anything about the developments in the Western world, had adopted the same standpoints with somnambulistic certainty. His pictures are characterised by floating forms, dynamics, insular entities, quite analogous to the world of traffic in the air and on the motorways, of dotted houses and the flowing organic lines of rooms and devices.”