Tonnis’ works are "supported with psychological knowledge" His earliest drawings reflect his interest in psychoanalysis and psychopathology such as, catatonic rigidity or the postnatal psychosis depicted in his 1980–85 collection. To "show the psychic as a second face" he "uses stitchings, masks and fragments of masks—they are sometimes barely visible" In 1986, he started to paint landscapes from literature like the "Magic Mountain " and portraits of writers and philosophers as William S. Burroughs, Virginia Woolf, Ludwig Wittgenstein, and more. His large scaletriptych"Frost" is "a material image in harsh black and white which depicts a literary landscape of snow and ice in different viewpoints a picturesque transformation of Thomas Bernhards 1963 novel". Since 2003 his work has become more meditative: "Geometric patterns in bright colors", consistent with Tibetan Book of the Dead and New Testament—the series of minimalistic "Meditation pictures". "Catwalk!" was exhibited at the Showroom Eulengasse in Frankfurt, Germany in 2007. The exhibition consisted of a series of collages created of cats' heads on women's bodies. The most recognizable bodies are those of Virginia Woolf "with big, sad eyes" and Kate Moss. In 2006 Tonnis set up a MySpace page dedicated to Thomas Bernhard, using pictures tell his biography. The theme of the page was Bernhard's motto "In the darkness everything becomes clear." In 2008 Tonnis started to contribute reviews on art to the style magazineDazed Digital, London. 2009: During the "Sommeratelier" at Kunstverein Familie Montez, Frankfurt, he created a painting for the performance "Who let the dogs out, Edith?". This "experimental collage of different media and arts" has been a dialogue with Heinrich von Kleist's play Penthesilea, directed by Hans-Jürgen Syberberg in 1988 with actress Edith Clever. With the mural of a golden cross on black and violet ground—divided into pixels—Tonnis has been one of 36 international artists who designed the "Pixelkitchen" in January 2013, a tiled room of 177.2 inches height at the Günes Theatre in Frankfurt. "All these artworks are glued, painted or nailed onto the walls." Tonnis' work is displayed in international publications to illustrate articles, essays, encyclopedic entries, etc.
Video
Tonnis started to make videos in 2006. His subjects have included William S. Burroughs, Thomas Bernhard and the poet Georg Trakl. Alongside these works stand the video series of "Dreams", "Electrical Pictures", and animals—exhibiting a pop, surrealpictorial language, often humorously staged. Since 2009 Tonnis produced 113 short documentaries about exhibition preparations, openings and artist interviews for the Kunstverein Familie Montez. They go together with a "Family Album", created out of video stills.
Solo exhibitions (selection)
1986: Zeichnungen, Galerie Das Bilderhaus, Frankfurt