Etching techniques are methods used in printmaking to create images on metal plates. The process typically involves coating a metal surface, such as copper or zinc, with a waxy ground. An artist then draws an image into the ground, exposing the metal beneath. The plate is then submerged in an acid bath, which bites into the exposed areas, creating grooves that hold ink. After etching, the plate is cleaned and inked, allowing the ink to fill the grooves. Finally, the plate is pressed onto paper using a printing press, resulting in a detailed print. This technique has been used by artists like Rembrandt and continues to be popular today.