Laser technique for the divestment of a lost Leonardo da Vinci mural

On 4 May 1504 Leonardo da Vinci was commissioned to paint a wall mural for the recently constructed Sala del Gran Consiglio adjacent to the Palazzo Vecchio of Florence. Several reports during the first half of the 16th century lauded this fresco (The Battle of Anghiari) as the most important sight in the city, and art historians suggest that it may have been Leonardo’s most significant work. Surprisingly, the mural was never again seen after the room was renovated in 1565. Recent investigative work has yielded evidence suggesting that the lost masterpiece may be intact somewhere on the large east wall of the present Salone dei Cinquecento, but walled‐in by substructures of the more modern Visari frescos. The probable delicate nature of the mural indicates that the removal of the final plaster covering without damaging the artwork may be exceedingly challenging. Consequently, we have been exploring a pulsed‐laser radiation technique that will accomplish selective vaporization of the plaster to reveal the surface of the Leonardo mural.