 A third copy (oil on canvas) is painted by Andrea Solari (c. 1520) and is on display in the Leonardo da Vinci Museum of the Tongerlo Abbey, Belgium.Because Sforza had ordered the church to be rebuilt hastily, the masons filled the walls with moisture-retaining rubble.The painting was done on a thin exterior wall, so the effects of humidity were felt keenly, and the paint failed to properly adhere to it.