The two plates used in printing of Unfinished Untitled Collagraph, as see here:
The plate on the right is inked both intaglio and relief and printed first, the plate on the right is inked intaglio and is printed second on top of the first print.
Collagraph Plate (left), 2007
Chipboard, glue, photocopies, spackling paste, polymer medium, 30.5x12 in
Collagraph Plate (right), 2007
Chipboard, glue, photocopies, tissue paper, gel medium, embroidery thread, polymer medium, 30.5x12 in