This inexpensive glass, that brought color to the Depression Era, was mass produced all across the country. Unlike the glass that had been manufactured previously, which was hand-blown or cut, this new type of glass was inexpensively produced by machines through a method called "tank molding." The tank molding process began by heating soda ash, silica sand and limestone together. This heated glass mixtures was then passed into pressing molds where it cooled to form the various glassware pieces (Kovel 3). The patterns that adorned the finished depression glass sets were often acid-etched or carved directly into these pressing molds. Other times, the machines enameled or silk screened the designs onto the glass (Pickvet 290). In addition, the colors that were so characteristic of this type of glass were created from the addition of metallic elements such as manganese, copper, cobalt, and chromium, as well as non-metallic agents such as sulfur, tellurium, and phosphorus (Pickvet 289).