Tapes ends of roller with masking tape to limit etching to specified width.
Cleans rollers preparatory to etching, using sponge, cleaning chemicals, and water.
Turns valve to agitate acid solution with compressed air and starts machine to rotate roller in solution. Periodically removes roller from acid bath, measures etch with depth gauge, and moves fingers over surface of roller and scans etching through magnifying lens to detect processing defects, such as pinholes and collapsing ground lines. Verifies depth of etch, using depth gauge. Scratches charcoal into etched cavities to make ground lines stand out and examines engraving to determine whether roller will print with desired effect. Transfers etched roller to cleaning vats, starts machine to spin roller in cleaning solution, and lowers brush to surface of spinning roller to remove acid-resistant coating.