I just stumbled upon this very interesting thread. Lots of opinions out there on plating. Here's my 10 cents on this also.
Having spent the past 26 years in the production plating industry both as a plater and a supplier, and having first-hand knowledge of the plating cycles used by a well-known high-end pen manufacturer, I can confirm that plating pens is indeed challenging.
Any electro-deposited metal used as a decorative plate including, chrome, silver, rhodium, pure gold and gold alloys, is at a major disadvantage from the git-go when used on pens. That problem is quite simple. Wear. And as any jeweler will tell you, the human hand is tremendously abusive to objects in contact with it. Even occasional contact like writing instruments. And then when you couple that fact with the relative thin nature of plating films, overcoming this problem is not easy.
The bad news for smaller enterprises wishing to do the plating is that there are no real easy and inexpensive ways to achieve superior results with plating, particularly when trying to achieve the unique, rich look of gold. Plating that is both beautiful and lasts is very expensive to do, whether one undertakes it themselves or seeks out a third party.
Without going into all of the details of the multi-layer processes and deposits used on high-end pens, if one is trying to keep the finishing process rather simple and the budget modest, the advice previously given to use chromium is probably the best. Its wear properties are excellent.
And if a gold-color is desired, it is very difficult to beat the performance of a plasma vapor deposited material like titanium nitride (sometimes referred to as TiN coating), as the bathroom faucet manufacturing industry will attest. On the downside, it has to be jobbed out but it lends itself nicely to small batches and small parts.
The bottom line is that if plating of lasting quality is needed then acceptable substitutes are indeed far and few.
Thanks for the opportunity to offer my opinion.
)] LOL