In 1970, Sonya Rapoport unlocked an antique architect’s desk she had purchased a decade earlier and discovered a trove of geological survey maps from the early 1900s. Using the information on the maps as a starting point, Rapoport began drawing and embroidering directly on the sheets in what she called her “Nu Shu language,” a visual lexicon the artist developed in reference to a tongue used only by women in the Hunan region of China. As the artist tells it in a 2006 essay, this moment marked an aesthetic shift, opening a new line of creative inquiry that would anchor her practice for decades. The artworks exhibited at Casemore Kirkeby, however, make clear that in fact there were inklings of these developments a few years prior to the artist’s revelatory moment with the maps in the desk. Here, in a selection of sculptural paintings made from 1964 to ’67, Rapoport uses upholstery fabric as her primary substrate, both for tracing the gaudy floral patterns in paint, and for stenciling curvilinear, abstract forms that mark the first instances of the artist’s transcription of her visual language into her artwork. Viewed alongside several drawings made during the same period, the exhibition reveals …