Research into non-traditional gilding techniques as a substitute for traditional matte water-gilding

This thesis examines the current practice of using traditional gilding techniques for compensation of losses in gilded objects and the problems that these traditional techniques generate for conservators undertaking visual examination and technical separation of such new in-gilding from original substrates. Although, non-traditional gilding materials and techniques have been available as alternatives since the 1980s, research has, until now, been required in order to determine the working properties of such synthetic materials under the demands made of them in gilding conservation. The research presented here aims to determine which polymers are sufficiently stable and reversible to successfully compensate original matte water gilded surfaces, thereby meeting the professional standards and conservation principles required by the conservation profession. The work involved methodical assessment of several stable synthetic materials used successfully in other conservation fields. Experiments undertaken as part of the study indicate that of the numerous synthetic polymer materials available to conservators, acrylic dispersion Plextol®B500, acrylic resin Paraloid®B-72 diluted in aromatic solvents, and polyvinyl acetate resin AYAF are the potentially the most useful. In the second stage of the research, the optimum concentrations of the solutions and the methods for activating the dried films were elucidated. Experiments showed that if applied using appropriate methods, all three synthetic polymers selected can be successfully used for compensation of losses in matte water gilding. Nevertheless, of the materials currently available to conservators, Plextol®B500 applied as an acrylic dispersion was shown to be the most versatile polymer available in terms of its activation and provided best surfaces for the application of gold leaf. The final sections of this work concerned testing of the aging behaviour of surfaces formed using the three selected synthetic materials, and comparing them with the aging characteristics of gilding using the traditional method. Results of measurements made using specially prepared frames exposed to extreme variations in humidity for twelve months in two different environments revealed no significant differences between the visual characteristics of gilding either visual appearance of the non-traditional and traditional gilding. These final tests demonstrated conclusively, for the first time, that synthetic materials may be used successfully in compensation of losses in matte water gilded surfaces