Conservar varnishes are a series of isolating and final picture varnishes and varnish kits based on materials and formulations used in current conservation practice. All these varnishes contain UV stabilizers
All Conservar varnishes contain hindered amine light stabilizers (HALS) or UV stabilizers. These act by interfering with oxidation reactions in the varnish that cause embrittlement and aging of the varnish. By incorporating HALS in Conservar varnishes a much more stable varnish is obtained. Accelerated aging experiments indicate that the lifetime is extended greatly. Monitoring of natural aging so far indicates that the stabilizer works as predicted by accelerated aging.
The HALS used in Conservar prolongs the lifetime of the varnishes dramatically. HALS are stable by themselves for a number of years, but once mixed with varnish in solution they are best used within a short period. For this reason we offer Conservar as kits so that all ingredients can be mixed fresh for use immediately. For artists reticent about preparing their own varnishes, we have also made these varnishes available as ready-made solutions in metal cans for maximum longevity and with the date of production printed on the label. The date lets artists know that they should use the varnish as soon as possible for best results.
Conserver Picture Varnish
Conserver Picture Varnish is a colorless, reversible varnish made from hydrogenated hydrocarbon (Regalrez) resin dissolved in pure, low-aromatic solvent and UV absorber and stabilizer. Conservar will not cross-link or yellow over long periods of time—much longer than natural resin varnishes. Conservar achieves optimum wetting of the paint surface to enhance colors, has minimum solvent action on paint, and maximum resin content for best coverage. It dries to a film that levels well and can be rubbed when dry just like traditional mastic or dammar varnishes.
E. Rene de la Rie and Christopher McGilinchey, “New Synthetic Resins for Picture Varnishes”, IIC Preprints to the Brussels Congress, pp. 168-173.1
Robert L. Feller, “Standards in the Evaluation of Thermoplastic Resins”, Preprints of ICOM in Zabreg (1978), pp. 78/16/4.