Fig. 2
a Reverse of the panel. The panel has been constructed from two joint oak planks (dashed line) and the growth direction of the two trees are shown by the red arrows. b On the central part of the panel (yellow square on a), the Antwerp Guild of Saint Luke (two hands and a castle, up-side-down) from two separate irons were identified. At the lower right part of the photo, the panel maker’s mark attributed to Guilliam Aertsen was found (up-side-down). c Macro photo showing a section along the edge of the panel. The area highlighted in green show the edge following micro-invasive surface preparation and the red arrow show the growth direction of the tree