Gilt leather conservation: A critical review to promote improved conservation strategies

Gilt leather is a decorative art form mainly used for wall hangings from the middle ages onwards. A leather support covered by thin silver leaves is coated with a yellow or orange-brown oil-resin varnish, providing the gold appearance. Further decorations are applied with various oil paints, glazes and varnishes. Complex ageing processes and the sensitivity of the specific layer build-up of organic and inorganic materials make conservation a real challenge. Conservation treatments practiced in the past resulted in negative side-effects over time, such as gloss and colour change (darkening), softening of the varnish and paint layers, and stiffening of the support. Gilt leather, of which only a fraction of the original output has survived, can be considered an overlooked and endangered part of our cultural heritage. Following an interdisciplinary expert meeting and research project (2016), this review discusses the most important conservation challenges, points out research directions and presents strategies for improved conservation treatments.