Franz Gertsch's paintings, executed from photographs, play with scale and reproduce only certain details, to modify and counteract the effects of realism. Gertsch's woodcuts, which are generally very large in format, follow the same artistic logic. He uses the "„Criblé" technique, in which a gouge is used to prick the matrix with tiny dots, recreating the form without contour lines or shadows. This coding of the image, similar to an underlying but perfectly visible weft, serves to confuse and distance the subject represented.

Perstwurz III is one of a series of engravings depicting enlarged butterbur leaves. The plant's name derives from the analogy between the shape of its leaves and the petasus, the flared-brimmed hat worn by Mercury. While the woodcut technique achieves a very delicate effect, the focus on the leaf evokes the way these perennial plants can prove invasive in damp environments.