When I restore a panel painting, at what point is it no longer the original?
I restore Renaissance panel paintings in Florence. Every working day I decide how much of the past to bring back and how much to leave alone, and every decision touches a question I first met in philosophy as the ship of Theseus, though in my workshop it never feels like a puzzle about words.
A fifteenth-century Madonna arrives with a split panel, flaking paint, overpainting from three earlier restorations and a varnish so yellow that the blue robe looks green. We stabilise the wood, remove later overpaint, fill losses and retouch them, so that from a distance you see an image and close up you can tell what is ours.
Is it the same painting? Physically, much of the paint surface is original, but a good deal of what the visitor sees is our interpretation. Aesthetically, it may be closer to what the painter intended than at any time in four centuries. Legally and in the catalogue, of course, it is the same object.
What interests me philosophically is that we have firm professional intuitions without a theory. We will replace a cracked support but never repaint a face. We fill losses but make the fills distinguishable. Those rules suggest that "the same painting" depends not on how much material is original but on which material, and on whether the image's history stays legible.
I'd love to hear from people in other crafts and traditions where this question takes a different shape.