Elements of the composition in the x-ray in the centre are slightly misaligned, which shows that the panel has been taken apart at some point and rejoined. There is a dense area around the head where a lead-based underlayer was applied over the priming in order to give luminosity to the face. Extensive carbon-based underdrawing is evident in the face in the infrared reflectogram on the right. It is clear that this was transferred from a pattern, reinforced with wet medium and then elaborated by adding short freehand lines to define areas of shadow and detail.
© National Portrait Gallery, London