A 500-year-old painting of a man praying to nothing (or at least nothing visible) lingered in storage at the Princeton University Art Museum. Chief Conservator Bart Devolder and I got talking. Something had to be missing.

The first time I saw, in an art conservation studio, the unframed edges of a 16th-century portrait, it felt something like having accidentally seen undressed a distinguished, older man in my professional field. (It was, of course, an “old master” painting). I was embarrassed for both of us.