Making the Invisible Visible: Conservation and Islamic Art

April 2–August 4, 2013

Conserving the Objects from Nishapur

Vicki Parry
Associate Conservator
The Sherman Fairchild Center for Objects Conservation

From 1935 until just after the Second World War, The Metropolitan Museum of Art conducted archaeological excavations at the site of the early Islamic city of Nishapur in Iran. In accordance with Iranian antiquity laws and excavation agreements, half of the excavated finds went to the National Museum of Iran in Tehran and the remaining material came to this Museum.

Although considerable efforts were made on site and later in the Museum in the 1970s to prepare this material for exhibition and publication, the use of unstable adhesives—primarily cellulose nitrate on the ceramics, architectural stucco and wall paintings and polyester resin on the glass—had made much of the collection physically unstable by the time the previous galleries were de-installed. In addition, the yellowing and darkening of the adhesives and surface consolidants previously used made it difficult to see original colors and designs. Also of concern were the elevated levels of potentially damaging soluble salts deposited during burial that had never been adequately removed. Finally, many ceramic and glass vessels had excessively large fills, which were sometimes misleading in shape and which limited access to break edges for compositional study.

Left: Ceramic restoration workroom on site at the Nishapur excavations; Right: Conservation of the collection today

In 2008, the Institute of Museum and Library Services awarded a matching grant to stabilize the excavated material from Nishapur. Thanks to this funding, the poor condition of most of the glass, ceramics, and stucco finds could be addressed while the entire collection was in storage. Prior to treatment, the condition of objects was documented with digital images taken in natural and ultraviolet (UV) light, the latter of which was useful in revealing the full extent of previous restorations. Modern paint and old adhesives were softened and removed by swabbing with solvents, allowing the shards to be freed of previous fills. Desalination of the ceramics in distilled water not only reduced soluble salt levels but also provided the least invasive and most effective way of removing excess restoration plaster from porous surfaces.

Natural (left) and UV (right) images of bowl (39.40.147). In the image on the right the old restoration paint fluoresces brightly.

Once ceramic fragments were cleaned and stabilized, they were rejoined using stable and reversible acrylic resins. In general, losses were not filled unless they were required to allow the vessels to be handled safely. All fills were done using reagent grade gypsum plaster or glass micro-balloons in acrylic resin.

Images of bowl (38.40.148) before treatment (left) and after treatment (right)

Glass objects, on the other hand, required transparent fills made with an epoxy resin that presented several technical challenges. This project benefited enormously from the expertise of Goradz Lemajič of the National Museum of Slovenia, who has pioneered the use of molded PVC film to create precisely contoured molds into which clear epoxy resin is injected. The technique of Mr. Lemajič, who served as a consultant to this project, has been further developed in the Museum for use on glass objects in the entire collection.

Left: Preparation for filling loss in in glass vessel (40.170.61); Right: Injecting epoxy resin in an area of loss in glass vessel (40.170.61)

Finally, in addition to ceramics and glass, carved stucco architectural panels and wall paintings required urgent treatment due to flaking and the discoloration of old adhesives and consolidants.

Ongoing Study of the Nishapur Collection

The development of new analytical techniques since the Nishapur material was originally excavated provides an opportunity to glean more information from this important archaeological collection. The composition of the glass from the site is being analyzed by Mark Wypyski, Research Scientist in the Department of Scientific Research, and preliminary research has been undertaken toward future technical studies of the ceramics and wall paintings.

Additional Reading

Kröger, J., Nishapur: Glass of the Early Islamic Period (New York, Metropolitan Museum of Art, 1995).

Wilkinson, C. K., Nishapur: Pottery of the Early Islamic Period (New York: Metropolitan Museum of Art, 1973).

———Nishapur: Some Early Islamic Buildings and their Decoration (New York: Metropolitan Museum of Art, 1986)