'Thames Police' was published in 1871 by Messrs Ellis and Green as part of 'Sixteen Etchings of Scenes on the Thames and Other Subjects', known more widely as the 'Thames Set'. Whistler could spend up to three weeks etching a plate. He captured every detail of his subject, inspired by his Coastal Survey training. In 1863 he met the Greaves brothers, Walter and Henry. He employed them to row him up and down the Thames to observe the river views in detail. Years earlier their father, Charles Greaves, had also done the same for the artist JMW Turner (1775-1851). New conservation work has enabled us to identify the paper Whistler used for these prints. Whistler was very selective about paper. This wasnt unusual. The Etching Revival had instigated a new interest in the aesthetic tone and structure of paper. Following Rembrandts example most etchers preferred Old Dutch paper or silky Japanese paper. Whistler searched stationers and old book shops in London, Paris and Amsterdam looking for these papers. Old Dutch paper was made from boiled and beaten rags drained on wire moulds. It was high quality with a ribbed texture and creamy in colour. Japanese paper was made from the bark of a mulberry tree. It varied in thickness and its tone could vary from pale cream to a pronounced yellow. The paper used for these prints can be identified by its beehive watermark. A watermark is an imprinted design which can be used to identify the papermaker. The beehive watermark is shown here in transmitted light (lit from beneath the paper). The beehive is associated with the Honig (honey) family of Dutch papermakers who owned mills in Zaandijk, North Holland. The coat of arms on this watermark was widely copied throughout the Netherlands and came to represent Dutch papermaking more generally. Initialled DEDB (beneath the beehive) this variation belonged to the Dutch papermakers De Erven de Blauw from about 1822. The design shows a central beehive motif surrounded by ornate scrollwork of leaves and flowers crowned with a fruit tree.