This book, a first edition of Recherches pratiques sur les différentes manieres de traiter les maladies vénériennes (1770) by Jacques-Joseph de Gardane (1726–1786), docteur-régent at the University of Paris, exhibits something called a cut-flush binding. As the online Language of Bindings Thesaurus explains, in such a binding ‘the boards and/or covering material are cut level (i.e. flush) with the bookblock in a single operation. When cut after covering, the covering material will, as a result, not have turn-ins, as they would be cut off when the edges were cut. If these bindings have boards, the edges of the boards will therefore be exposed’, as here.
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