Modern and advanced methods of removing wax and wax-resin adhesives

Cleaning the original canvas from the adhesive composition is the main objective while retreating paintings consolidated using wax-resin adhesives. This publication discusses techniques for removing wax and wax-resin adhesives that have been developed and introduced into conservation practice over the past five years. All of them are based on the use of materials that are safe for artworks and conservators, and are also highly effective. Such materials are presented by systems in which the cleaning composition (solvent or mixture of solvents, aqueous solutions of surfactants, chelating agents, etc.) is enclosed in a “carrier” (for example, a gel). The article describes in detail enzymes (class of esterases), as well as micro- and nanoemulsions as new and promising cleaning compositions. Various classes of polymer gels take a role of “carriers” in some of the proposed methods. Thus, employees of the University of Warsaw presented a patent for the removal of wax-resin adhesives from the canvas structure using a nanocomposite organogel based on poly-N-isopropylacrylamide (pNIPA). Other work uses “twinchain” polymer networks based on polyvinyl alcohol (TC-PNs-PVA), which were recently developed by Italian researchers. A non-woven microfiber material Evolon CR is also an effective “carrier”, the action of which is based on strong absorbent properties and capillary effect. The authors of the article describe the methods of working with these materials and talk about the successful experience of their use in the practical conservation of easel oil paintings in museum collections in Europe and America.