This section highlights the scientific tests and investigations undertaken on the earlier version over the past 40 years.
• A testament to Leonardo’s interest in geometry, the ‘Earlier Mona Lisa’ aligns perfectly with the ‘Golden Ratio’. In addition, the innovative ‘Hidden Technique’ investigation reveals that both portraits must have been painted by the same artist. Furthermore, the earlier version precisely fits the Goldblatt thesis, inscribes itself in the logical progression of Leonardo’s ‘Harmonic Geometry’ and fits with Sauteur’s theory of perspective.
• Ultraviolet light, infrared luminescence, infrared, false colour infrared, infrared reflectography, X-radiography, carbon dating, and lead-white measurement by gamma spectroscopy examinations all confirm, especially when considered together, that the painting was most likely executed at the beginning of the 16th Century.
• Comparisons based on the digitisation of both the earlier and Louvre Mona Lisas scientifically prove that the faces in each work were painted by the same artist.
• Leonardo not only described his techniques for painting on canvas, but clearly used this medium himself. The hand-woven linen canvas, or Rheims cloth, on which the earlier version was painted, has similar characteristics as those upon which Leonardo painted his famous drapery studies in the 1470s.
• All pigments used in the painting were common to Leonardo’s palette, and were available at the beginning of the 16th Century. The palette for this painting remains true to his own directions and theories.
• Underdrawings found on this painting signify that this is an original work, and not copied from another.
• The Louvre version has characteristics of the glazing techniques which were developed after 1508, entailing that this could not have been the Mona Lisa described by Vespucci and Vasari.
• Leonardo da Vinci was primarily left-handed. Intense magnification indicates brushstrokes of a left-handed artist in several places.
• While the Lumiere Technology study indicates that both the earlier and Louvre versions of the Mona Lisa could have been painted by the same artist, the Asmus investigation goes as far as proving this is the case.
Perhaps because of its unique place in the world of art, this earlier portrait of Lisa del Giocondo by Leonardo has likely undergone more examinations and investigations of a serious scientific and technical nature than almost any other. From simple X-rays to the latest, most sophisticated tests available, no effort has been spared in these fields to verify the integrity, identification and authorship of the painting. This great work has met every reasonable criterion.
The painting, and all its physical components, such as the canvas support, and all the pigment layers, from the gesso and grounds all the way through to the surface not only exactly fit the time and the place, but conform with so much precision to Leonardo’s own vocational description as given in his Treatise On Painting.
From a scientific and technical perspective, every test, examination and analysis over the last 40 years shows that there is no reason to disqualify this painting as an autograph Leonardo. In addition mathematical and spectral analyses, especially when taken together, show that significant sections of the painting must have been executed by the same artist as the Louvre painting.