Etching: When you imprint a design or pattern into metal. When I made my piece I drew a design with sharpie on the metal and it was dipped in acid. Patina: A sorta film like color on a metal. I made my piece I put a piece of metal in a bin full of vinegar chips and it made the metal a blue/green color.
Etching
Patina
Etching is a imprint of a design that you draw. With the Etching, you have to make sure the metal is clean but with the patina you don't.