Boeckl's nudes are mostly charcoal and pencil drawings. They seem like sketches, delicate and frail - as though hovering weightless in space. Their singularity places them amongst the greatest achievements in 20th-century European drawing, and there is little to compare with them in European art. Besides representing the human body, Boeckl is concerned with forcing it open to produce something new: "The nude drawings of the period 1918-1922 occupy a special place in my work. At that time, Schiele's drawing cast its spell over the whole of the young generation. Permeated with my best feelings, these drawings resemble small mines penetrated by a rare ray of sunshine. The seed works its way in between the open layers. I have drawn a lot; just once, a tiny result."
Otto Benesch, former director of the Albertina, also saw in Boeckl's nude drawings "germ-cells of new evolving form":
"These drawings have an element of growth; a process of becoming takes place in front of the viewer's eyes. The bodies shimmer, come into bloom, as a plant unfolds."