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Etched plates are eaten with acid, and engraved plates are hand cut.

You are Exactly Right!

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It's the difference between simply scratching (needling) through an acid-proof coating (called etching ground) to make a line, and then letting acid do the work and, in engraving, using a sharp, hardened steel tool (called a burin) to cut into the metal to make a line.

Etching also provides a range of tonal techniques, and engraving is more limited in this regard.

Congrats!

- GM