Following the coating of titanium nitride, the same process is used to cover the parts of the watch that need to be gold – using real gold. The result is a shimmering lustrous finish of gold that looks like solid gold but that is also protected against corrosion caused by salt, air, perspiration and pollution. The environmentally harmless PVD process also offers a long-term guarantee against tarnishing or staining and does so with no toxic residues emitted.
One of the best advantages with a PVD process when it comes to gold, is that it keeps the price of lustrous watch much lower than solid gold and so is very cost-efficient. The other advantage is that the watch is more protected against scratches if it hadn’t been covered first with a layer of titanium nitride.
For its black PVD coating on stainless steel, Longines uses a deep black layer of chromium carbide, which is also more resistant to wear and tear, and corrosion because of its hardness and oxidation levels. The coating, which can be up to a single micron in thickness, is designed to be purely decorative and should not be subjected to repeated impacts.
Because PVD coating is a sophisticated process, it is the preferred way to achieve the desired color and luster on steel. Whatever collection of a Longines PVD watch is chosen from, it will look and feel like gold years to come.