Hesse defined the word ‘schema’ as ‘synopsis, outline, diagram. general type, essential form, conception of what is common to all members of a class.’27 While the evenly-spaced, balanced grid of her eponymous sculpture (fig.9) may be read in terms of Hesse’s definition, her interest in ‘diagram’ and ‘essential form’ are also expressed in the meticulous planning and rigor with which she approached its design, including her choice of material. In addition to drawings,28 Hesse made numerous ‘test pieces’ (fig.10) prior to the execution (by her own hand or otherwise) of many of her works. She used these ‘material studies’ to experiment with the structural properties of rubber, papier-mâché, Sculp-Metal, and other matter so as to determine, in part, their potential usefulness in crafting specific forms like hemispheres, cylinders, and various vessels. For Schema, she chose to work in latex, as she did many of her sculptures dating from the late 1960s and about which she stated: ‘the materials I use are really casting materials, but I don’t want to use them as casting materials. I want to use them directly, eliminating making molds and casts ... I am interested in the process, a very direct kind of connection