Abstract

Four unvarnished oil paintings by the abstract expressionist artist Joan Mitchell were studied and conserved at the Carnegie Museum of Art (CMOA) and the Indianapolis Museum of Art at Newfields (IMA). These paintings, Sans Neige, Sans Neige II, Low Water, and Diabolo (neige et fleurs), all dating to 1969, share a similar color palette and degradation phenomenon in thickly applied cadmium yellow brushstrokes. Samples from three works were studied using Raman and FTIR spectroscopies, stereo microscopy, and scanning electron microscopy with energy dispersive spectrometry. A protocol was developed at CMOA for the consolidation of the crumbling yellow matte impasto through the careful application of funori with gentle manipulation of the paint. Acrylic fills were used to mimic Mitchell’s paint handling in areas of loss, and the fills were textured and inpainted using funori with ground original paint samples that had detached and could not be reattached to the painting’s surface. The treatment was successfully repeated at the IMA through online collaboration with CMOA during the COVID-19 pandemic. Samples were analyzed to identify, for the first time, the artist’s late 1960s palette. Waxy nodules observed in cross sections of the crumbling yellow paint were determined to be zinc stearate agglomerates, focused along break edges and incipient cracks, strongly suggesting a relationship between the instability of the paint and these zinc soaps.

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