french_marbleMarbling is the art of printing those swirly designs onto paper. You might assume that it was done by photographing an original and printing it offset. No doubt for mass production items — candy boxes or whatever this is what would be done, but for deluxe book production, only the original will do. But how rarely do we nowadays get to use printed endpapers, or even a color end? Marbled papers are (obviously) expensive — each one unique, printed as follows (from Marble Art):

 1. Some alum is dissolved in water. This is sponged onto each paper to be marbled, and the paper is allowed to dry. The alum is what will bond the color to the paper.

    2. A thick liquid, referred to as the size, is made by blending a type of gelatin (carrageenan) with water.

    3. The size is poured into a shallow tray.

    4. Several colors of ink or paint are sprinkled onto the surface of the size. They float on the surface because they are lighter than the thickened water.

    5. A stick is used to stir the floating colors if desired. Various combs and rakes may also be run through the colors to make more intricate patterns.

    6. A sheet of the alum-treated paper is gently laid onto the surface of the size, and it absorbs the floating colors. Only one print can be made.

    7. The paper is lifted off, rinsed, and hung up to dry.

This Folio Society video gives a good impression of how marbled papers are created. 

Here’s a link to a site offering a marbling kit for sale at £60.