Etching has been used for nearly 500 years as a printmaking technique where ink is forced through lines etched into a copper or plastic plate to create prints. Originally used to decorate armor, etching involves using a needle or sandpaper to scratch designs into a surface, then applying ink which is transferred to paper under pressure. The document provides instructions for creating an etching, including drawing and rubbing designs, cutting shapes, applying tape for texture, inking the plate, printing, and adding details like watercolor once printed.