This isolating PVA varnish was designed to serve as a fixative for retouches, and to protect fresh retouches when the painting is varnished. It is a carefully balanced formulation of vinyl resins and fast-drying solvents which are ideal for application by spraying. It can be applied to a recently varnished painting without casing, “spotting”, or “orange peel” (*). Once the isolating varnish has dried (1 to 2 hours), the painting can be varnished with a suitable furnishing varnish, such as BEVA® Finishing or Matte Varnish or UVS Finishing or MATTE Varnish. Because the isolating varnish dries rapidly, it does not penetrate absorbent surfaces, such as those of modern and contemporary paintings, and causes only minimal color change. Because its vinyl resins are colorless, stable, and clear, G. Berger’s Isolating Spray Varnish can be used to ‘isolate’ acrylic paintings from any overpainting or varnishing which they might require for their protection. Although the application of PVA on acrylics is irreversible, such a coating might nevertheless prove useful as a protection for the surfaces of these paintings since PVA's do not discolor.
(*) “Inpainting Using PVA Medium”, by G.A. Berger, in “Preprints of Contributions to the IIC Brussels Congress", 1990.