The authentication of a painting cannot be based on Science alone, but the results of certain scientific tests can disprove an attribution. Over the last 35 years, to the Foundation’s knowledge, every recognized test and examination has been performed on the earlier Mona Lisa.
A testament to Leonardo’s interest in geometry, the earlier version of ‘Mona Lisa’ aligns perfectly with the ‘Golden Ratio’. In addition, the innovative ‘Hidden Technique’ investigation reveals that both portraits were painted by the same artist. Furthermore, the ‘Earlier Version’ precisely fits the Goldblatt thesis.
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.
Scientific comparisons of both the Earlier and Louvre Mona Lisas point to them both being works of the same artist. However, there are significant differences which signify that neither one is a copy of the other. (This important area of investigation is dealt with in greater detail in the section: ‘Critical Comparisons’.)
When the historical circumstances of Leonardo are considered, and noting his keen interest in, and experience with, the use of canvas, it is arguably most logical that Leonardo would have used a canvas support for his earlier version of ‘Mona Lisa’. The hand-woven linen canvas was relined at a later date, for the purpose of strengthening it for longevity, and for maintaining the masterful integrity of the work. X-rays have confirmed that there has never been any damage to either the painting or the canvas support.
Leonardo not only described his techniques for painting on canvas, but clearly used this medium himself. The hand-woven linen canvas, or Reims cloth, on which the portrait was painted, has the same characteristics as those upon which Leonardo painted his famous drapery studies in the 1470s.
All the pigments that were found on the earlier version of ‘Mona Lisa’ were available and in use at the beginning of the 16th Century. Leonardo’s palette, and the manner and sequence in which he mixed and applied his pigments, follows closely the meticulous instructions he wrote in his Trattato, his Treatise ‘On Painting’.
This has been recognized in the course of all the intense examinations through which the painting has been subjected. Many of these pigments were known to have been in use even decades earlier. It is conspicuous how Leonardo’s palette for this painting remains true to his own directions and theories.
Evidence has also been provided that the ground pigments used for Leonardo’s earlier ‘Mona Lisa’ were also employed by him in some of his other famous works.