The Conservator’s Toolbox: X-radiography of a Japanese cloisonné enamel

At the Walters, we regularly take x-rays of objects, paintings, and books; this allows us to have “x-ray vision” and look inside objects.

An objects conservator in the Conservation Window with a set of cloisonné enamels which shows how they were made and holding the x-ray of the Dragon vase, the subject of this post. The Dragon vase is on the desk in the nest of tissue, lying down to keep it safe from falling over.

Recently in the Conservation Window, an objects conservator was talking with museum visitors about how conservators use x-radiography to non-destructively learn about how objects were made and also assess their condition, using a 20thcentury Japanese cloisonné enamel vase as an example.

This vase was made in Japan, in 1905 and is 4 ¾” tall. It entered the Walters collection in as a gift from Mr. William A. Fisher III.

The vase is actually made out of copper metal, which is not visible though, because the surface of the vase is  covered by the design of the dragon and the black background. The designs are made from glass that has been fused to the copper by heating  in a kiln.  To create the designs, silver wires were attached to the surface of the copper vase; these wires make the outline of the design. Then, powdered, colored glass called glass frit was mixed with water and packed onto the surface. The whole object was then fired in a kiln, melting and fusing the glass frit onto the copper vase,  leaving the it completely covered by a layer of glass, also called enamel. After a lot of polishing, the surface is now very shiny.

This vase is a specific kind of cloisonne enamel, called basse-taille. To create the figure of the dragon, a thin sheet of silver would have been laid on the copper vase. Green translucent enamel, or glass, covers the silver foil, giving the dragon’s scales a shimmery effect.

We had a question about the silver used for the design. Was it applied to the whole surface of the copper vase underneath the enamel, or only on the areas of the vase where the dragon design would be?

X-radiograph of the Dragon vase (left) with a detail of the dragon’s head (right). The area around the dragon’s head and whiskers is brighter white because of the silver sheet that has been placed only under the area of the dragon. The red arrow points to the edge of the silver sheet.

X-radiography helped us answer this question. In this x-ray of the vase, the brightest white lines are the silver wires used to outline the design. The area around the dragon is brighter white than the background. This tells us that the silver has been cut and purposefully placed only under the dragon, not over the whole vase.

By using x-radiography which is fast, easy, and doesn’t harm the object, we can answer questions like this which adds to the knowledge about how an object was made.