The Museo del Prado is presenting the conclusions of the technical study and restoration of its version of La Gioconda
Monday 20 February 2012
Infra-red reflectography and examination of the pictorial surface under raking light showed the existence of a landscape beneath the black background. Chemical tests concluded that this background was an area of later repainting dating from no earlier than 1750 and that there was an organic layer between it and the landscape underneath that had preserved the latter in excellent condition. Despite the difference in the quality of the painting in the two works, the landscape in the Prado version reflects the colours and evanescent forms of Leonardo’s landscapes. The enormous interest of this copy lies in the fact that from the under-drawing to the final layers it repeats the working method used to create La Gioconda without aiming to be a forgery of it. A comparative analysis of the infra-red reflectographs of the original in the Louvre and the Prado copy reveal identical details beneath the pictorial surface that point to a parallel process of creation. The figures are practically the same in size and shape and, more importantly, each of the corrections to the under-drawing in the original are repeated in the Prado version. They include the alteration to the shape of the waist, the position of the fingers and the outline of the veil and of the head. There are also lesser modifications including slight changes to the form of the cheeks and neck.
A traditional copyist would have transcribed what he saw on the surface but not what was concealed beneath it. However, as the under-drawing in this case reveals, the artist who painted the Prado version drew the same elements as Leonardo, including ones that were not subsequently painted and are thus not visible on the surface
The results of this study thus point to a member of Leonardo’s studio and to the fact that the two works were painted in parallel. With regard to a possible attribution, the pictorial style is not comparable to those of pupils or followers of Leonardo such as Boltraffio, Marco d’Oggiono or Ambrogio de Predis, who had very defined artistic personalities. However, the work can be stylistically located in a Milanese context close to Salaï (1480-1524) or possibly Francesco Melzi (1493-1572/73), who were Leonardo’s most trusted pupils and who inherited his work.
In addition, the extremely high quality of the materials used in the creation of the Madrid version suggests that it was an important commission, unlike other known copies of La Gioconda, which are all later and clearly reproduce what was by then a famous original. Technical analysis has demonstrated that the Prado version was executed in parallel to the original, giving rise to the hypothesis of a “workshop duplicate”, executed at the same time and with direct access to Leonardo’s gradual process of execution.
After analysing the information derived from the technical study, the Prado proceeded to restore the pictorial surface, removing oxidised varnishes that had given the painting a yellowish hue, particularly in the flesh tones. This procedure restored the original tonalities as well as the volumes of the materials and the transparent effects of the veil. After cleaning was completed the Museum’s restorers removed the black layer of over-painting that completely covered the background. This was carried out gradually using organic dissolvents until this layer was completely removed. Once the landscape had reappeared and in order to obtain the correct transition between the figure and the background, re-establishing unity and balance between them, repainting over the veil and part of the hair on the left side of the head was also removed. This functioned to recover the transparency of the veil and the view of the landscape through it. This particularly important zone of the painting thus regained its original, ethereal quality and conveyed a much better sense of the air and space surrounding the head. Given the very good state of the painting, only a small amount of chromatic reintegration was required in the final phase of restoration and was limited to small, insignificant losses.