O papel japonês no facing de pintura a óleo sobre tela

This dissertation focuses on the study of the behavior of japanese papers when applied to the facing of oil easel paintings, in conservation and restoration. The acquisition of japanese papers by conservator-restorers of easel paintings is mostly based on their thickness and price. Which reflects in the use of the same paper in works that, perhaps, would require a different material. In order to combat this reality, it is necessary to enrich the knowledge about the japanese paper raw material and its production so that it becomes aware that these factors can be determinant for the final quality of the product. Otherwise, we will have to subject ourselves to the information provided by suppliers, which are not always sufficient or correct. There is still little literature on this subject, although Japanese paper is the most used material. For this reason, this investigation is justified. The objectives of this research, in a first stage, and through the bibliographical survey, to determine the raw materials and methods of production of japanese paper, as well as to study the evolution of the facing and the materials used for this purpose. In a second phase, of experimental character, it is intended to test different types of japanese papers – Gampi, Mistsumata, Tosa Usushi, Kinugawa Elfenbein, Bib Tengujo, Moldelspan – for facing in different oil paintings on canvas (textured/ non-textured, different historical periods) in order to determine the characteristics and behaviors of each paper so that the conservator-restorer of easel paint can take them into account in the making of treatment proposals. In addition to the japanese papers will also be tested another material - Wet-strength Tissue - currently used and approved by the supervisor of this work. The tests will also be carried out with different adhesives and solvents, since these can also be determinants for the improvement of the process. After the tests it was found that Wet-strengh Tissue and Modelspan proved to be the best papers in non-textured zones. With regard to textured zones, three papers stood out: Bib Tengujo, Wet-strength Tissue and Modelspan. The first one stands out in higher impasto zones (≥ 3 mm) and the rest in lower impasto zones (