Found materials are central to Hesse’s early sculptures. After August 1967 and her discovery of latex at Cementex on Canal Street, her work shifts. This material, which encompasses a shift from liquid to solid, brings diversity to her work. She begins to make her own planes and shapes, and to explore anew the relationship between tension and flex that rope and string, in its various manifestations, had previously allowed. This concern for a material that can be both malleable and solid also appeals to Wilke, who uses latex, as well as ceramic, gum, and rubber for her sculptures. Wilke in 1974 acquires a loft on Greene Street in Soho, and also finds materials on Canal Street, some at the celebrated art supplier Pearl Paint. She orders latex from General Supply and Chemical Corporation in Cambridge, Massachusetts. Both artists exploit the skin-like effects of latex and play with the different textures that can be achieved with the material. More broadly, both artists are interested in playing with the surfaces of their sculptures, experimenting with color and glaze, as well as the raw effects. This attention to materials provides a hinge that connects both Hesse and Wilke to other artists interested in process. If Hesse is now better known as a “Process Artist,” together with Richard Serra and Robert Morris, Wilke insists on the importance of her own process as a primary frame for understanding her artworks, as demonstrated in her description of works like the one-fold gestural sculptures.

1967–70
When Hesse first uses latex, she begins by molding it, creating a series of small works or tests. These works are comparable to Wilke’s vulvic sculptures and suggest that Hesse’s first experiments with latex comprise basic interventions into the material.

Subsequently, Hesse begins to approach the material differently, building the latex up in layers. In a diary entry from September she describes the process of making the floor-based sculpture Schema and its related test pieces:

Am in the process of casting a sheet of rubber (on Sol’s table) 3’6”. On top of which sit semi-spheres 2 1/8” in diameter. It is all transparent to translucent, clear rubber. Looks like that vinyl type hose. It’s a long process, painted on with brush and having to wait ½ hr. to one hr. between coats. Although this varies depending on size of what I cast, thickness etc. The sheet will need 10 coats.²³

On November 16, 1968, Hesse’s first solo exhibition of sculptures opens at the Fischbach Gallery. The exhibition is titled Eva Hesse: Chain Polymers, evidencing the significance of her use of plastics. Hesse shows Schema, Sequel, Repetition Nineteen III, Accretion, Sans II, Accession III, and Stratum, as well as drawings and test pieces. She writes of the exhibition:

I would like the work to be non-work. This means it would find its way beyond my preconceptions.
What I want of my art I can eventually find. The work must go beyond this.
It is my main concern to go beyond what I know and what I can know.
The formal principles are understandable and understood.
It is the unknown quality from which and where I want to go.
As a thing, an object, it acceded to its non-logical self.
It is something, it is nothing.

Despite Hesse’s interest in these newer materials, her use of more mundane things is also recognized and brings her into relation with the material experiments of the historic avant-garde. In 1970, Ennead is exhibited at the Sidney Janis Gallery in String & Rope, alongside works by Marcel Duchamp, Man Ray, Bruce Nauman, Pablo Picasso, Robert Rauschenberg, Lucas Samaras, Kurt Schwitters, and others.

1960–79
Wilke’s experiments with the effects of different and new materials for her sculpture begin while she is still in art school. Although she works with ceramics, “creating layered vaginal forms in natural browns and terracotta,” for most of the 1960s, she looks to plastics as early as 1960.26

I started making fiberglass pieces in my senior year in college because its plasticity allowed me to create curvilinear and architectonic form simul-taneously... I painted them black in the tradition of metal sculpture... Those sculptures were abstracted arm- and leg-like structures reaching up with big separate centers connecting them, and they were definitely vaginal. I named them with erotic titles (Embouchure, Nymphae, Candida, Oncos...) I was aware by the time I was twenty that they were vaginas and we talked about it in college at the time.²⁷

The “C.O.” in the title of this work stands for Wilke’s partner at the time, the artist Claes Oldenburg with whom she is in a relationship for eight years.

Like the large ceramic fields, Wilke makes these sculptures in series, attaching them to different backings from painted boards to postcards. In the postcard works shown on the wall, sometimes the forms correspond to the background image as if the sculptures occupy or take over the scene, as in Corcoran Art Gallery (1976); at other times they extend beyond the postcard, but take their organization from the base image, whether that be the geometry of an Atlantic City square, as in Atlantic City Boardwalk (1975), or the irregularity of rocks in a creek as in Catskill Creek (c. mid-1970s).

Wilke makes the game for the exhibition Artists Make Toys at the Clocktower Gallery in New York which is supposed to lead to a series of multiples and Wilke exploits the potential of a money-making edition by stipulating that each game requires the artist to be present for a fee. As she is adorned with gum sculptures, Wilke becomes “starified”—a punning play on her becoming a celebrity, and therefore a rich artist, and the scarification that the gum sculptures looked like on her body—the cost of renown. The game is never made into a multiple, but Wilke continues to explore starification in her series of S.O.S. photographic performance works.