The anodic coating on significant surfaces shall be continuous, smooth, adherent, uniform in appearance and shall be free from powdery areas, loose films, discontinuities such as breaks and scratches or other damage. Defects in the coating that result from base metal conditions defined in 3.1 shall not be cause for rejection relative to the requirements of this specification. The size and number of contact marks shall be at a minimum consistent with good practice. The location of contact marks shall be in areas of minimum exposure to service environmental conditions when important to the function of the part, i.e., rack marks should be on the I.D. of cylindrical parts. The color of the coating shall be black, unless otherwise specified. Parts made from wrought (bar) stock shall be bright and shiny. Parts made from die casting material will be duller and of poorer color quality than wrought material. Colors other than black shall conform to generally accepted color standards; i.e. Sandoz