AIC's 46th Annual Meeting

Italian-born American artist Rudolf Stingel is well known for his monochromatic abstract oil paintings with delicately textured, silver or golden-iridescent surfaces. Since the late 1980s, the artist has developed the technique from solely tulle-textured effects on oil paint to that of incorporating ornamental stencils, now often referred to as his 'carpet paintings.' These paintings are extremely vulnerable to oxidation. Accidental touching during handling will cause the later appearance of dull, corroded stains on these highly reflective surfaces. The metallic enamel paint he used throughout the years to achieve the metallic effect on various colors of oil paint was initially developed for sealing industrial metal appliances. The copper-zinc alloy pigments in this paint have a leafing character, which is based on their disk shape and repellent character when in contact with the non-polar solvents in the paint system (best achieved using Xylene). In a painted film, the pigments will orient themselves in high concentration on the surface (leaving the body of the film pigment-free), and seal the film with a fine, almost solid layer of pigment flakes. This creates a highly reflective, gilded character to the surface. Since the paint was developed for industrial purposes only, the durability of its visual properties was of no concern to the fabricator. These special-effect pigments are extremely vulnerable to outside oxidants – whether air borne or physically transferred – as they are not embedded and protected in their binding medium. Consequently, the paint layer will gradually shift from a cool golden tone to a bronzed appearance over time. Fingerprints, water drips or scuff marks further accelerate the oxidation process, turning the surface dull, dark brown or greenish. At Contemporary Conservation Ltd., we are often faced with these locally oxidized areas, especially on the golden paintings. Normal avenues of treatment – chemical reversibility, physical removal of material, or the addition of material - are not applicable. The corrosion is irreversible; polishing or sanding are only destructive; and even local inpainting or gold-leaf application cannot recreate an sufficiently brilliant appearance. Even though the artist kindly provided samples of his paints, their golden tone no longer matches the naturally aged appearance of the original work. The proposed presentation will tell the story of the investigation undertaken to develop a conservation treatment for these works. Several obstacles were faced, including finding a method to protect the intact, yet naturally aged surrounding, and enacting appropriate health and safety measures when using the paint system which contains mostly Xylene. In an effort to match the gold to the aged condition on a particular work the leafing pigments were artificially aged outside of the paint system. Transferring the treated pigments back into a solvent system revealed the loss of the leafing character of the pigments, which was accommodated by separating the application of binding medium and pigments. Additionally, due to the fact that the paint's recipe was changed in 2004, the artist is now exploring similar tests himself, in order to adjust the system to his desired tone and aesthetic choices.