Marbled paper

BibliOdyssey has a nice essay with a dozen photos of examples of marbled paper.  My only memory of such paper is from the interior of book covers, but there were other uses:

They served, for example, as wall coverings; as linings for the interiors of trunks, boxes, wallets, musical instrument cases and other containers; for covering boxes and other receptacles; as ornamentation in the panels of cabinets, furniture, and even harpsichords; as wrappings for toys, drug powders, and other consumer goods; for enclosing blank books used for writing, and for other stationary purposes; and as shelf papers for lining cupboards and cabinets and for many home-decorating purposes.
(From the introduction to: 'Marbled Paper: Its History, Techniques, and Patterns' 1990 by Richard J Wolfe, widely regarded as the leading authority on marbling.)

The history of marbling is fairly obscure. It is thought that the decoration first appeared in Japan by at least the early 12th century, from a process known (still) as Suminagashi ('sumi' means ink and 'nagashi' means floating, thus 'a pattern formed by floating ink'). The craft may have arisen in China independently or was imported from Japan very early on in the piece. Certainly, the inference in all the references is that a marbling technique was first practised in Japan.

Perhaps a century later, marbling appeared in, or near, Afghanistan, becoming an artform of the Persian and Ottoman worlds, centred in Turkey. Again, the marbling process may have been imported from the far East via the Silk Road trade route or it arose independently. The distinct Turkish marbling technique is known as Ebru and even the origin of that word is contentious, connoting either cloud art or water surface in Farsi or a related regional dialect.

The Suminagashi and Ebru forms of marbling are simplistic and rudimentary in comparison to the diverse and technically precise art that emerged subsequently in Europe. In this case it is known that the technique was transplanted from Turkey to France, Italy and Germany in the 15th and 16th centuries, where a much larger body of craftsmen developed the technique over a few centuries.

For a video showing how the marbling effect is created nowadays, see this post.