Q. Some of the information that comes with the jewelry products we import from Spain states that they are coated with a gold IPG material. Why use an IPG coating? B.J.
A. I do marvel at the way marketing organizations come up with initials and names for products. In this particular case, your vendor is talking about a process known as ion plating, which is a type physical vapor deposition (PVD). The part to be coated is placed in an inert gas, quite often argon, along with a coating material. An electrical arc is used to evaporate the coating material, and the evaporated particles deposit on the surface of the part to be coated. One of the claims for this process is that the gold deposited is more resistant to wear compared to conventional electroplated gold. I really do not know if this is true.
The direct answer to your question is that IPG is terminology for gold ion plating. If you Google ion plating, you will find a number of references that discuss the process in more detail.