Some things i have thought of in gold-money are small bits of gold being embedded in another material.

Like a dollar bill, with a window (plastic) with like a piece of gold foil, encased between two sheets of plastic, embossed into some shape, detail.

Also, may be done in coin form (thicker plastic) with a piece of gold embedded in it.

It may work, it may not. It may never come about because of bitcoin. Or maybe it will because of it.