Christian Koesters Schrift „Ueber Restauration alter Oelgemälde“ und die Praxis des Restaurators Johann Jakob Schlesinger

“Ueber Restauration alter Oelgemälde“ by Christian Koester and the Practise of Johann Jakob Schlesinger – a Contribution to the History of Painting Restoration in the First Half of the 19th Century The painting restorers Johann Jakob Schlesinger (1792–1855) and Christian Koester (1784–1851) advanced the development of their profession in the German-speaking countries in the first half of the 19th Century. They did restorations for the collection of paintings owned by Melchior and Sulpiz Boisserée in Heidelberg as well as for the Königliches Museum in Berlin – today’s Gemäldegalerie, Staatliche Museen zu Berlin. Koester was the author of one of the first books in German, dealing with the restoration of paintings. Its value as a source of restoration history was redefined in the context of the first monograph about Johann Jakob Schlesinger. The insight into the historic details enlarges our knowledge of the techniques and materials used in the restoration of paintings in the first half of the 1800’s.