“One approach is connoisseurship, the ability of a true art expert with a refined eye to discern paintings by the master. Unfortunately, connoisseurship over the years, both in this case and others, has created more disagreements than it has resolved, and it has sometimes been proven wrong when new evidence arises. Another approach is scientific and technical analysis, which has been made more potent recently with infrared reflectography and other tools using multispectral imagery. Isaacson, Walter. Leonardo da Vinci (p. 312). Simon & Schuster. Kindle Edition. ”
