Treatment

The primary treatment objective was physical stabilization of the rendering layers and their attachment to the underlying support. The plaster surround was removed mechanically. Removal of the rigid supports that prevented consolidation from the reverse was considered but rejected as too invasive to the object. Instead, stabilization of the rendering layers by means of grouting was favored (Fig. 4).

A 20% (w/v) solution of polyvinyl butyral (PVB) in equal parts acetone and ethanol, with addition of one part gilder's whiting and one

Figure 2

Bearer of Good Wishes, Ming dynasty, Taoist wall painting fragment, ca. 1600-1650,

201 X 82 cm, prior to conservation. Memorial Art Gallery of the University of Rochester (86.117).

Figure 3

Bearer of Good Wishes (shown in Fig. 2), crosssectional detail of original rendering layers and added modern support layers prior to conservation.

Figure 4

Bearer of Good Wishes, after conservation.

Part glass microspheres7 (to two parts PVB), provided the desired properties of an adhesive and gap-filling material. In preparation for grouting, loose aggregates were removed from the edges of the painting; and the exposed rendering was consolidated using a syringe application of a 5% (w/v) solution of PVB in equal parts acetone and ethanol.

The grouting mixture was delivered by syringe from the perimeter of the painting while the painting was positioned on edge at an angle of 60-70° from horizontal. Ethanol was first injected into the rendering layers as a wetting agent to encourage the PVB grout to fill the voids. The grout was injected along the elevated edge of the painting, which encouraged inward flow. Viscosity of the grout was adjusted by addition of solvent. The painting was returned to horizontal and weighted for at least twenty-four hours; the operation was then repeated along the opposite side of the painting. Four complete grouting cycles were required to fill the voids, thereby stabilizing the rendering layers. Finally, the edges of the rendering were treated with a PVB filler composed of the 20% stock PVB

Grout, small additions of kaolin and fumed silica, and ethanol as needed to form a workable putty.

A variety of consolidants were tested for insecure areas of the matte paint surface. Two consolidants showed satisfactory results. A 5-10% (w/v) solution of Ethulose in water—applied by brush, faced with a Japanese tissue, and weighted overnight—left no discernible tide lines or darkening of the paint surface. Better results were observed using a 5% (w/v) solution of Acryloid B-72 in xylene, applied in a glove-bag enclosure, according to a technique published by Hansen, Lowinger, and Sadoff (1993).8 In this method, the atmosphere within the enclosure was saturated with xylene vapor for forty-five minutes prior to consolidation. In this xylene-saturated enclosure, a 5% (w/v) solution of Acryloid B-72 in xylene was locally brushed over insecure areas. This process was repeated several times until the paint surface was consolidated. In some areas, curling and lifting paint was brought into plane by application of gentle pressure from a heated spatula over a silicone-release Mylar polyester sheet. Care was taken not to burnish or compress the paint film.

Sensitivity of the paint to mechanical and solvent abrasion precluded the use of many aqueous and nonaqueous systems, gel systems, and chelating agents for removal of accumulated grime and overpaint. Standing dirt and grime were removed with a kneadable eraser called Groom/stick. Additional dirt and grime were removed using a 25% (v/v) solution of water in ethanol (with 2% v/v diacetone alcohol) from the few stable areas of the paint surface using cotton swabs or pads. These areas included the headdress, which contained a thick, well-bound layer of malachite. Otherwise, no attempt was made to remove embedded grime or degraded surface coatings. Selected overpaint and overfills were removed using a 20% (v/v) solution of water in ethanol. Later reinforcement of the black calligraphic lines could not be safely removed but were later muted using thin glazes of retouching.

Retouching was limited and was carried out using Flashe 1300 colors. Exact color matching was avoided; instead, a compatible tone was used that would visually unify the area of damage and would be clearly distinguishable from adjacent, original paint. Losses that exposed white ground were not filled, leaving subsequent inpainting recessed. Losses that exposed the gray rendering layer were not compensated.

Before treatment, the piece had been framed and exhibited as an easel painting; however, this manner of exhibition was reconsidered in favor of exhibiting the work as a fragment of a larger wall painting. To increase rigidity, a maple-wood surround was fitted to the plywood sup-ports.9 Gaps between the painting and surround were filled with PVB putty, and diluted putty was painted onto the maple over an isolating layer of shellac. The putty was applied in four layers over a period of several days to reduce cracking and shrinkage, then sanded to the level of the maple surround. Multiple layers of neutral-gray latex paint were applied to unify the background, which was recessed from the painting by one-quarter inch (0.635 cm).

Although the Chinese wall painting fragments described here are unrelated by geographical and historical origin or restoration history, each has been visually and structurally altered over time and through human intervention. Surface examination and technical analysis provided an objective basis for evaluation and implementation of treatment materials and procedures. Budgets and deadlines limited the extent to which technical analysis and treatment could be undertaken. Conservators of The Female Attendant operated under a low budget with an impending exhibition deadline. By contrast, the budget for technical analysis and treatment of Bearer of Good Wishes was significantly higher. Moreover, Bearer of Good Wishes was treated over a two-year grant period that was easily extended when it became necessary. In consideration of the fragile condition of these works and the limited resources for research and treatment implementation, treatment of these paintings was restricted to stabilization of the renderings, consolidation of the paint surface, limited removal of grime, and minimal compensation of damage.

Discussion of Both Painting Fragments