In the treatment of both paintings, reattachment to the supports and filling of voids were favored over more comprehensive consolidation. Several factors influenced these decisions. First, an overall consolidation of the rendering layers would have required removal of the plywood backings, an approach that was considered too invasive and potentially damaging. Second, generalized application of a consolidant could have penetrated and adversely affected the saturation or reflectance of paint layers. Third, by exhibiting the paintings horizontally or at an incline, the need for more extensive consolidation was avoided.
Selection of the materials and methods used to reattach the rendering layers and fill voids was based on the severity of detachment and testing of a variety of adhesives on test blocks (acrylic and PVA resins, acrylic dispersions, and cellulose ethers). While the rendering layers in The Female Attendant were detaching locally along the fragment's perimeter, those in Bearer of Good Wishes were detaching more generally and crumbling to fine powder and coarse aggregates. Testing demonstrated that Acryloid B-72 bulked with glass microspheres was an appropriate adhesive filler to remedy the edge delamination observed in The Female Attendant. By contrast, polyvinyl butyral bulked with glass microspheres proved an appropriate grouting material for Bearer of Good Wishes—the material proved successful on mock-ups and in the treatment of other wall paintings (Hanna, Lee, and Foster 1988). Further, the high molecular weight of the polymer decreases penetration into the rendering layers.
World History
