Hi yoyology,
'Rub 'n Buff' is a paste used to simulate or repair gold leafing, it will go onto almost any surface. It is a cheat but a lot easier than trying to put gold leaf onto plastic believe me.
Rub'n Buff works well and goes an awful long way, follow Ron's advice and clean up with a safe solvent, clean your hands and work surface carefully or else everything for miles will have little gold smears or spots on. Keep out of reach of kids, not only for health and safety reasons but also for wealth and sanity reasons, there will be gold everywhere and not where you want it and it will not come out of rugs or furnishings easily.
Don't even think about asking how I know this last bit, it is still a slightly touchy subject.
It is made by AMACO, there is what ie either a product code or perhaps a US phone number on the tube, it is (800) 374-1600.
I can't remember where I got mine from but I expect that it was a decorating supplier in the UK so you should be able to find it somewhere like Home Depot or of course any other reputable, or at least well stocked, store of a similar kind. If not there then try somewhere like Michaels or Ben Franklin craft stores.
I hope this goes some way to answering your question.
Cheers, John