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.
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.
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-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.