How is this picture framed?
The panel on which the portrait is painted and the carved frame are one single piece of oak. This is referred to as an integral frame.
Old nails, driven into the edge of the panel all the way round the outer edges of the frame are visible in the x-ray images.
It is not clear what purpose these nails may have served or when they were added. Historical documentation suggests that the painting originally had a red painted cover, this is based on the record in a 1516 inventory of the Palace of Margaret of Saxony in Malines where the picture was displayed.
It is possible that some of the nails are related to this cover, and were used to secure it in place and adjoin it to another structure. However, it is also possible the nails may be a later more modern addition.
Similar integral frame portraits of English monarchs exist in the Society of Antiquaries including Edward IV and Richard III.