Technical Study





An initial examination with ultra-violet light (fig. 19) revealed that the surface was covered with a thick layer of varnish and large areas of overpainting that produced a blackened, opaque image. This information was confirmed by technical studies carried out in the Museum’s Technical Documentation Department.33 As noted above, in the technical analysis of the work both the Infra-red reflectography and X-radiography (figs. 20 and 21) confirmed the existence of a large area of overpainting on the left side of the panel and showed the presence of a female saint with a halo, a martyr’s palm and a lamb at her feet, identifiable as Saint Agnes. Also revealed was a donor holding a scroll. The existence of underlying painting was visible to the naked eye in some areas where the paint surface had been damaged, as it was in an area of overpainting that had become thinner, thus allowing the letters on the scroll and a fold of the donor’s clothes to show through.

The thick overpainting covered a diagonal zone that ran from the two mountains framing the figure of Christ to the bottom of the panel but did not affect the mountain with the Apostles or the sky. The overpaint was particularly visible in the spaces between the trees in the centre of the painting, making their branches thick and heavy. The work also had some conservation problems including areas of wear and paint loss, which are referred to in the section on technique in this text.

Having exhaustively analysed the problems presented by the panel and with the help of the technical resources available at the Museum, we embarked on its restoration in order to return the work to its original appearance, eliminating the imbalance resulting from the overpainting between the two areas into which the composition had practically become divided, revealing the hidden figures and recovering the work’s pictorial quality and aesthetic unity.

The fact that the support was well constructed, the outstanding quality of the oak and its appropriate thickness for the dimensions of the painting meant that the structure of the panel had survived well over time and therefore did not require restoration.

The technical studies undertaken provided key information on the underlying paint layers such as the existence of the figures beneath the overpaint. They did not, however, yield any information on the state of preservation of these figures. X-radiography and Infra-red reflectography confirmed the quality of their design while the small number of isolated stratigraphic micro-samples that were taken showed that the painting underneath was quite thick. Nonetheless, three options had to be considered: that the painting underneath was in very poor condition and had therefore been covered over; that during that procedure the surface had been deliberately eroded in order to make the paint subsequently applied on top of it adhere better; and finally, that this was simply a change to the composition or a pentimento on the part of the artist and that the figures were never completed.

In the light of this situation, and once again with the ongoing support of technical analyses, we decided to proceed with the elimination of the overpaint, bearing in mind from the outset of cleaning that the limits of the treatment could only be established through careful visual analysis, i.e. attentive observation of the physical difference between the materials of the lower layer and those of the overpaint.

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