... brass/stainless stel/Aluminum,Printed brass/stainless steel/aluminum4) Plating : Can be gold , nickel , copper , ... engraving, printing, laser, etching 5) Electric-plating: gold, antique gold, matt gold, silver, antique silver, matt silver, nickel, black nickel, brass, ... copper, dyed black, chrome, dual plating, or any others ...