Previous studies carried out at the National Gallery of Art have detailed the modifications made in the course of creating the painting we now know as The Apostle Paul, dated to the mid-to-late 1650s, and presented technical and stylistic evidence that the painting was executed in two stages. Rembrandt initially depicted a scholar in his study, but later revisions by another hand – possibly involving participation of the workshop – transformed the painting into an image of the Apostle Paul. New technical imaging methods were employed at the NGA to help resolve lingering questions about how specific areas of the painting looked during the first stage. The imaging methods used included X-ray fluorescence imaging spectroscopy (macro-XRF or XRF-IS) and visible and infrared (400 to 2500 nm) reflectance imaging spectroscopy (RIS). These methods revealed evidence that aided understanding of specific features within Rembrandt’s first-stage composition – namely a small lectern, a slighter figure with perhaps a more elaborate costume – as well as the unexpected presence of stylised leaves in the background to the figure’s left. Paint samples collected in 2014, after the technical imaging, confirmed that smalt was used in depicting the leaves. The combined application of diverse modalities of scientific imaging and analysis have afforded a greater understanding of Rembrandt’s original composition and the successive stages of subsequent modifications.