In the central x-ray broad brushstrokes can be seen across the panel which relate to the priming layer. Although the piece of wood that is held in place with nails at the top-left corner appears very dark compared to the rest of the panel, the continuation of the brushstrokes in the priming layer shows that it must be an original piece. The highlights on the dark dress fabric appear much lighter and clearer in x-ray, whilst the right-hand image taken in ultra violet light shows areas of retouching along the right-hand panel join.

© National Portrait Gallery, London