Between 1962–4, Hesse developed a looser, more gestural drawing and painting style, often incorporating colourful, collaged elements. Surrealist artists, such as Roberto Matta and Arshile Gorky, may have influenced her use of fluid, almost random marks in the series of drawings and paintings. The sense of energy and dynamism between the forms is enhanced by her use of arrows to further emphasise movement. The fluidity of her style is matched by her flexible approach to the physical components of the works. For instance, she would sometimes take drawings apart and reassemble them as collages, perhaps returning to them later to move collaged elements or even turning them upside down.
Hesse met and married the sculptor Tom Doyle in 1961. In 1964 Doyle was invited to work in Kettwig an der Ruhr, Germany, under the patronage of a collector. Hesse was curious to return to her country of origin, so the couple decided to take up the offer. Hesse spent the first six months in Europe visiting galleries and exhibitions, and established contacts within the lively Düsseldorf art scene.
In early 1965, she developed a series of colourful paintings and gouaches, again using the idea of abstracted forms within compartments. The shapes have both a mechanical and an erotic quality, suggesting machine parts and reproductive organs. Hesse was drawn to Surrealist art, particularly works by Marcel Duchamp such as The Bride Stripped Bare by her Bachelors, Even 1915–23, in which sexual desire is portrayed as a driving mechanical force upon the body.
The framing device that appears in the earlier drawings is now transmuted into a box or cube form. It appears not only in the paintings and drawings, but also in Hesse’s first experiment with three-dimensionality, Untitled 1964.