It’s easy to recognize a painting by Amedeo Modigliani. The elongated face and neck. The almond-shaped eyes. The sitter wrapped in warm ochres, browns, and burgundies. Modigliani’s style is so distinctive it can feel like a brand. It has also produced one of the most fertile grounds for forgery in the history of art. What tends to get lost is the actual object: the type of canvas, how it was made, and when exactly the painting was produced. The Pinacoteca Agnelli, which holds Nu couché (1917–18)—one of the artist’s great nudes—now presents it alongside three other Modiglianis on loan from the Centre Pompidou and the Staatsgalerie Stuttgart. All four works are subjected to scientific analysis. The weave and warp of the canvases is examined, the origin of the fabric rolls is reconstructed, and a new method for dating the paintings is introduced. —Elena Clavarino