The study of this regal portrait evidenced its creation as a model for dozens of versions of the effigy of the monarch in a three-quarter pose. As it is an official portrait, there are many versions of varying quality, but technical photography made it possible to reveal a whole series of changes not present in other works. These alterations mainly concern the position of the figure, but also the position of the hand holding the pendant, initially conceived higher up, as shown by the infrared photograph. The image obtained through infrared photography with transmitted light — illuminating the work from the reverse — made it possible to identify the repositioning of the monarch’s head, while the X-ray led to the detection of the removal of a buttonhole that fastened a sash on the shoulder, which was also reinterpreted.
The mapping of all these changes and their digital superimposition made it possible, when compared with the rest of the versions, to demonstrate that this was the only one presenting these reinterpretations. The results of the stylistic comparison and the analysis of the materials that make up the work demonstrate that this canvas is the one Goya painted between February and April 1789, documented but, until this study, of unknown whereabouts.