Plating services apply a thin coating of metal to the surface of a substrate in order to improve conductivity, prevent rust and corrosion, and facilitate soldering. There are two basic plating techniques: electroplating and electroless plating. Electroplating applies DC power to the plating particles so that they adhere to the substrate. Electroless plating deposits plated metal from a specialized salt solution. Some plating services perform processes that produce layers with a high hardness or abrasion resistance relative to the substrate, or compared to other coatings or finishes. Others specialize in plating layers with a soft or high purity. For example, soft gold or silver coatings are used to provide lower electrical contact resistance, an important consideration in some electrical and electronic applications. Plating services are located across the United States and around the world. Many meet International Standards Organization (ISO) requirements or automotive, aerospace, military, or OEM specifications.