Borealis (1988–92)

The imagery and coloration in the metal painting series Borealis, was produced through chemical reactions (which Rauschenberg called “corrosions”), sometimes with the addition of acrylic paint. Tarnishing agents, such as acetic acid and ammonium salts, were brushed onto brass, copper, or bronze surfaces, resulting in a muted range of colors: green, brown, or black, depending on the type of metal support. By painting or silkscreening with a tarnish-resistant medium before applying the tarnishing agent, the artist created coloristic variations between the tarnished and untarnished metal. Additional silkscreened images were applied with acrylic-based inks.