4 DISCUSSION

When it was realized that the removal of the original support from the paint and ground layers was necessary, a treatment was devised using materials that could be applied and removed without affecting one another. The temporary adhesives of starch paste and n-butyl methacrylate were removed with water and petroleum benzine that would not disturb the bond made with the polyvinyl acetate “Hot Melt” adhesive on the reverse of the thin ground layer. The temporary support on the front of polyurethane foam incorporates no solvents, and its exceptionally light weight did not endanger the painting's fragile conformation. Since the slight warmth produced during the foaming might have softened the n-butyl methacrylate facing adhesive, an isolating layer of thin aluminum foil was used. The emulsion glue used to assemble the balsa core panel required only slight pressure during its drying time. The wax-resin adhesive bonding the 100% cotton fiberboard to the new Japanese paper support can be dissolved in petroleum benzine and naphtha to ease disassembly of the lamination components should future reversal of the treatment be required. The initial varnish application, the water-soluble filling putty, and the inpainting medium were all applied in solvents that would not affect the “Hot Melt” adhesive.