Grant Barnhart has some recent images up of partially erased tanks on paper. He wrote an update on his website about them, saying "I've added some new tank drawings to the site. Each tank is erased graphite and enamel on canvas. The mark making is inspired by a combination of Raushenberg's transfer drawings and [the] Willem De Kooning erasing.. No matter how hard I try to erase the tanks the image still remains. I find the ghost image to have more signifigance and importance than a fully conceived rendering." 
Robert Rauschenberg, Untitled, 1968
The NY Times wrote about Rauschenberg's transfer drawings, saying "The transfer technique, which he [Robert Rauschenberg] took up in 1958, had remarkably few moving parts. It involved soaking newspaper or magazine clippings in solvent, laying them face down on drawing paper and then hatching back and forth across them with a dry pen nib. The results dazzle; in a flickering, almost strobelike effect, images seem to rise to the surface like memories through a scrim — or through the static of a television set. " His "Erased DeKoonig" piece from 1953 is exactly what it sounds like, and as one could imagine it never reproduces well in books or online. You can learn more about it and why it is a commonly referenced cornerstone of modern art - frequently being referenced by minimalists and post-modernists - here.
