Making the Invisible Visible: Conservation and Islamic Art

April 2–August 4, 2013

Case Study: Rooster Ewer

Sarah McGregor
Associate Conservator
The Sherman Fairchild Center for Objects Conservation

Fig. 1. Digital photographs taken before treatment

This ewer in the form of a rooster was most likely made in Kashan in Iran in the thirteenth century using stoneware, a composite of crushed quartz, glass frit, and white clay (fig. 1). While the body and neck were formed on a potter's wheel, the head was made in a mold and the handle was modeled separately. After drying, the head and the handle were luted onto the body using a clay slip. A blue underglaze paint was applied to delineate the features on the head and decorate the body with vertical stripes that alternate with the tan color of the stoneware body. A clear alkaline glaze was then applied over the entire surface before the ewer was fired. The fine craquelure seen in this glaze may have occurred during cooling when the glaze and the ceramic body did not shrink at equal rates resulting in what is known as a poor "fit."

Fig. 2. Digital photograph taken with ultraviolet light. The whitish blue is the fluorescence from the adhesive and the flat pale yellow fluorescence is from the paint and plaster fills.

Prior to its acquisition in 1919, this ewer had been repaired after sustaining damage to the body, handle and feathers of the rooster's crown. In addition, the glaze had fallen off in isolated areas. At that time, the cracks in the glaze had been consolidated with an unidentified adhesive and the areas of glaze loss, as well as the small losses in the crown, had been filled and disguised with paint that often extended over original surfaces as revealed when viewing the surface under ultraviolet light (fig.2).

Fig. 3. A digital photograph of the ewer before treatment. The extraneous fragment is located between the yellow arrows.

While the adhesive joins in the body were well aligned and appeared to be stable, the joins in the handle were not. The middle section of the handle is lost and had been replaced with a poorly fitting handle fragment from a similar vessel forming a pastiche (fig. 3). There were marked differences between the color, texture, and thickness of this extraneous fragment and the rest of the ewer.

Fig. 4. The mock-up of the new handle made with plasticine clay.

In consultation with a curator, the decision was made to replace the handle fragment with a new fill that would more accurately represent the more delicate proportions of this ewer. It should be noted that the handle is meant to represent a rooster's tail consisting of one or more feathers with curled ends. After looking at comparable examples in other collections it was decided to make a single feather strand. A mockup of the new handle was made and molded to produce a plaster cast (fig.4).

Fig. 5. Digital images taken after treatment.

This new plaster handle was joined in place with a stable acrylic resin and painted so that it matches the color of the ewer but can be discerned upon close inspection (fig. 5). The old restoration paint was removed and the losses also were painted with acrylic emulsion paints.

Additional Reading

Keblow Bernsted, Annie-Marie, Early Islamic Pottery—Materials and Techniques. Archetype Publications Ltd., 2003.