REF

REF
Gresto is a rectangular abrasive block (8 x 5 x 2cm) that cleans, polishes, smooths, or causes copper and zinc plates to become matte, but it can also be used on such materials as wood, ceramic, and stone. Adding water, soap, or a turpentine-based product strengthens its effects.
3 grit sizes are available:
Coarse - 70 / Medium - 140 / Fine - 240
Specific References
Polyester litho plates 33x50cm 10x
200ml aluminium can / screw lid
Mitsu-bishi dermatograph black pencil