Retouching a Retouched Painting: Evaluation and re-treatment of historic retouchings in the conservation of a painting by Lavinia Fontana

Abstract

A major conservation and research project on The Visit of the Queen of Sheba to King Solomon by Lavinia Fontana was completed at the National Gallery of Ireland in Dublin in 2021. The painting, a large-scale oil on canvas (256 x 325 cm), was one of a number of pictures restored in the late 1960s by a team of conservators from the Istituto Centrale del Restauro in Rome, who came to Dublin during the establishment of the first conservation studio at the Gallery. The visiting restorers brought novel ideas and materials with them from the Istituto that would shape the Irish approach to conservation for decades to come. The prevailing ethos at the time in Italy was based on a minimal intervention approach with the use of novel, synthetic materials that had not yet been introduced to the collection of the National Gallery of Ireland.  The painting, after treatment by the Istituto team, recorded material evidence of a particular moment in the development of conservation in Italy and Ireland. Large areas of historic loss and damage across the surface of the painting had been reintegrated by the Italian restorers with the application of retouchings in the tratteggio style, also known as rigatino, using a Paraloid-based medium. In some cases, portraits and other significant details in the image were fully reconstructed by the retouchings. Underlying instability required the removal of some of these retouchings during the most recent treatment, but others could be retained if desired. With the help of archival images and documentation, a decision-making model was developed to evaluate the quality and historic value of these retouchings and to determine which to preserve, which to modify and which to remove. Reduction of retouchings often necessitates replacement, and the partial preservation of the historic retouchings brought further factors to bear on the decision-making model for the chromatic reintegration of the painting. A return to the tratteggio technique was chosen for the larger instances of loss compensation in the treatment, albeit with a finer hatching so that the newer reintegration remains distinguishable from the historic one. This was complemented with a pointillist technique over textured fillings for smaller and shallower losses.  Furthermore, where blistering and heat damage in the paint layers resulted in uneven topography, a third auxiliary technique was used. The desired texture was found when testing Paraloid-based gels on a mock-up and applied to bring continuity the surface texture in these areas of the painting. With this approach we intend to meet the conservation needs of the object, restore the legibility of the image and retain the evidence of the historic intervention of this founding team of Italian restorers at the National Gallery of Ireland.