Finding the cause of deterioration in a pair of Imari vases. A serial conservation mystery, episode 1

In the conservation lab we have two very large and impressive-looking vases. The vases from Wilton House, Salisbury have come to the conservation lab to be repaired as they are both structurally unstable. The conservation team turned detective in order to discover what was causing the instability. In the first episode of our conservation blog, you’ll find out how the conservators uncovered the symptoms and solved the case.

The patients

The vases are late 17^th Century examples of the popular Japanese style ‘Imari’ identified from the distinctive decoration of cobalt blue under-glaze and gold and red over-glaze. This style of Japanese porcelain was produced as export for the Western market, indicated by the style sharing its name with the Japanese port from which it was transported: Imari, Saga.

The symptoms

The vases have large cracks running from the base, nearly ¾ of the way up the sides. The cracks weaken the structure and cause the significant instability. Along the edges of the cracks and round the base of the vases are missing areas of decoration and glazing. As the vases are no longer in one piece, they are not safe to display in this condition. While the cracks remain, these vases continue to be at risk of breaking apart.

The suspects

Although the symptoms of deterioration could be clearly identified, their cause remained a complete mystery. The conservation team could treat the symptoms. We could fill the large cracks and repair the glazing but without discovering the cause of the damage and finding a suspect, we would be taking a big risk. Further deterioration could occur in the future and the vases become irrevocably damaged.

Milbourne House on the outskirts of Malmesbury is a fascinating, rambling old 17th century mansion, almost bewildering with its maze of passages, staircases and changes in floor levels. In December several of us attempted to unravel its mysteries by delving into its myriad nooks and crannies, no mean feat as it is one of the larger buildings that Wiltshire Buildings Record has tackled in a while.  We eventually found the central core of two rooms with a rear stair turret that had been built for John Estcourt in the mid-17th century.  Looking into the history of the Estcourts reads like a modern-day soap-opera.