Efflorescence on the Paintings of Edwin Austin Abbey: Examination, Analysis, and Cleaning of Surface Bloom on The Spirit of Light

Abstract

The Yale University Art Gallery (YUAG) collection contains more than 600 paintings by the American artist Edwin Austin Abbey (1852–1911). Over half of these works exhibit efflorescence that appears as a white surface haze. An upcoming exhibition focusing on the preparatory paintings of Abbey and his contemporaries during the American Renaissance has provided the opportunity to study these efflorescing paintings to gain insight into Abbey’s painting technique and to inform future conservation treatments. As part of a larger research project, this study aimed to understand how the observed efflorescence relates to the painting materials and techniques used in Abbey’s oil-on-canvas study The Spirit of Light and to explore approaches for reducing this efflorescence during treatment. The structure and surface of the painting were studied with a stereomicroscope, and multilayer samples were analyzed with field emission scanning electron microscopy – energy dispersive spectroscopy (FE-SEM/EDS). The morphology of the efflorescent material was imaged, and the elemental composition determined, with FE-SEM/EDS. FE-SEM/EDS revealed that the efflorescent material was composed of layers of lifted plates that contain carbon and zinc. The ground layers and efflorescent material were characterized with Fourier transform infrared spectroscopy (FTIR), FE-SEM/EDS, and gas chromatography/mass spectrometry (GC/MS). Analysis revealed that the plates were composed of crystalline zinc carboxylates, as opposed to the more frequently encountered free fatty acids. The silicone-based gel Shin-Etsu KSG-350Z was found to be an effective solution for reducing the efflorescence layer from the highly soluble and underbound paint layers.