In 2012, SFMOMA conservators Amanda Hunter Johnson and Paula De Cristofaro tested different papers and painting techniques that replicate the surface effects of Robert Rauschenberg’s Untitled [glossy black painting] (ca. 1951). This process built on preliminary materials testing undertaken in 2010. The mock-up process helps the conservation team understand how the work was constructed, providing information that will guide future treatments of the painting’s fragile surface. The video also includes footage of a treatment undertaken in 2012 to replace the insert supporting the work’s canvas.