Some notes/caveats regarding your questions: Be careful using acronymns. In common usage, "PVA" in the US usually refers to polyvinyl alcohol; in the UK, it usually refers to polyvinyl acetate...two entirely different critters. The "B-72" and similar designations are usually proprietary grades of a product designating viscosity/molecular weight...such terms are often used as conversational shorthand amoung people who each know what the other is referring to. Bedacryl is probably a polybutyl methacrylate polymer. "B-72" is probably an ethly methacrylate copolymer (Paraloid or Acryloid) _Materials for Conservation: Organic Consolidants, Adhesives and Coatings_, by C.V. Horie, Butterworths, is a good introduction to these sorts of materials. A conservator (I am not one) should be consulted regarding the applicability of any of these materials to your specific needs. Gregory Brown University of Nebraska State Museum [log in to unmask]