Cristo diante do Sumo Sacerdote

: a problemática das costuras na conservação e restauro de pintura sobre tela

Abstract

Christ before the High Priest, of unknown author, is a tenebrist seventeenth century painting, from Torre de Moncorvo (Bragança) which has been studied and has suffered a conservation and restoration treatment at the Portuguese Catholic University of Porto. During the research of the historic and artistic context of this work, we discovered that it was a copy of a painting by Gerrit van Honthorst (1592-1656, Utrecht), an important Dutch painter not just for his artistic quality but mostly for the way he painted night scenes illuminated by candlelight, creating a dramatic effect marked by strong chiaroscuro contrasts. Besides this copy, we have found three others at Estremoz (Portugal), Madrid (Spain) and Bordeaux (France). The painting in study has been analysed in terms of artistic materials and techniques, including textile fibres identification and pigments, fillers and binders characterization. In terms of conservation, the correction of significant deformations (mainly in the lower zone) along to a vertical seam led to the need of undoing part of the seam. The fragility and the high content of acidity in the textile support, due to hydrolysis and oxidation mechanisms, justified the lining choice. The high risk of detachment of the ground and chromatic layers led to its consolidation. Also, at the pictorial level, the lacunae were filled and retouching was made. The problems caused by de adhesion of a new support to canvas with seams have been solved in different ways by conservators over time. Thus, in a second part of this research we did a survey of several proposals and we evaluated their efficiency by making test models, and submitting them to tensile tests until rupture occur.For the lining of the test models, we used the same adhesive (BEVA 371 O. F.®) and four types of reinforcement fabric: linen, sized linen, polyester and sized polyester. We concluded that it is preferable to apply a mid-material to offset the seam’s relief and also that the used polyester textile has an inferior performance when compared to linen.

Date of Award	16 Feb 2016
Original language	Portuguese
Awarding Institution	Universidade Católica Portuguesa
Supervisor	Maria Aguiar (Supervisor)