Valve tags are used to prevent errors and accidents by identifying and color-coding valves. Tags are available in both blank and preprinted forms. Blank valve tags are made of aluminum, brass, stainless steel or plastic. Aluminum tags are often dyed a variety of colors for color-coding. Brass tags can be imprinted using steel stamps while stainless steel tags can be customized with an engraver. Plastic tags are lightweight, noncorrosive and impact resistant.