Sheffields SPI E-Nickel Black Plating:
SPI E-Nickel Black is a proprietary plating and blackening process for many commercial and decorative applications.
It is designed to blacken low or medium phosphorous electroless nickel. The finish reflectivity of the SPI E-Nickel BLACK is dependent on the surface finish of the base material. A matte surface finish of the base material, with a low thickness of electroless nickel, will provide a less reflective surface, whereas a highly reflective surface finish of the base material and a higher electroless nickel thickness will provide a higher reflectivity. It creates a thin black nickel oxide film that is free of loose smut.