He created textural richness with grattages, collages, engravings and varnish, physically building up surfaces in an effort to explore the transformative qualities of the materials used. (visual-arts-cork.com)
In Untitled (Mustang Series)(2004), where Rush embellished the printed surface by hand - applying chine collé, thick textures of entangled grapevines recall the enigmatic forests of the frottage drawings and grattage paintings by the Surrealist Max Ernst (1891 - 1976). (therivardreport.com)
He also created the «grattage» technique, in which paint is scraped across canvas to reveal the imprints of the objects placed beneath. (prabook.com)