Jim Dine, Artist, The Glyptotek Drawings

Eraser crumbs fixed to the surface of a drawing.

"In all of the drawings, evidence remains of Dine's use of erasers to subtract layers of friable media, whether it is a subtle highlight or a large area of subtraction with remaining eraser crumbs visible. The crumbs that remain on the drawings are adhered into place by subsequent layers of fixative and are reproduced in printed form as an abstract tonal pattern. A tonal pattern was not Dine's intention when he left these crumbs on the drawings but instead, as Dine mused, "[I] just left my tracks."

Sandpaper used on the surface of a drawing. 

"Subtracting media is not unique to this series, but rather is a constant for Dine in the creation of drawings. In the past Dine has described a drawing as "something you . . . carve . . . out of the paper rather than laying it on top."v This working method typically prescribes the use of thick resilient supports."

Text and image source is The Morgan Library and Museum.  Link here.