The first step in etching involves covering a sheet of metal with an acid-resistant, waxy material. The metal is typically copper or zinc, but steel is also sometimes used. The wax or varnish, known as a ground, covers the sheet of metal. The ground can be either a hard ground, which is melted onto the sheet of metal and allowed to harden, or soft ground, which is applied as liquid and is impressionable once it dries.
After the ground is applied, the artist carves the image into the ground. The goal is to expose the metal that will make up the image, as this will later be dipped in acid to cause a chemical reaction. An artist uses a tool called an echoppe, which is a sharp needle designed to carve fine lines into the ground. It is important to remember than in a print, this image will be reversed.
When the desired image is carved into the ground, the metal plate is dipped into an acid solution. The acid will react with exposed metal, a process known as biting. The longer the plate stays in the acid, the deeper the image will be imprinted. The ground will keep the acid from the rest of the plate as this process occurs. Afterward, the plate is washed to clear away the acid, then dipped in turpentine, or a similar chemical, to remove the ground.
Finally, ink is applied to the metal plate. The parts of the plate that will remain uncolored are wiped clean, while the incisions are filled with ink. The print is made on a damp piece of paper and allowed to dry. Depending on the type of metal used, the background may be white or gray (copper and zinc wipe much cleaner, while steel will print a gray background).