POLISHED GOLD Titanium letter Specifications: Stainless Steel alloy 304 substrate with a 30 micron layer of titanium nitride applied to the surface through a process called vapor deposition. This process actually bonds the two materials together providing a dense and durable finish that we guarantee it for 10 years. A highly reflective finish similar to a mirror. Its gold color makes it an excellent alternative to natural brass. It does not require a clear-coat and is excellent for use outdoors. We guarantee the finish for 10 years.