You can go to a broker and exchange your gold for the currency of the day. So gold is money or gold becomes money. History has proven time and time again, that unlike the paper dollar, a dollar defined in law as a weight unit of gold is the monetary standard which simultaneously provides all the primary functions of true standard money being:
a. a stable store of value,
b. a stable measure and unit of account, and
c. a universally accepted means of payment.
But no perfect monetary system can be fashioned in an imperfect world like we have today, with over sight by imperfect people.
"dollar convertible to gold" is still warranted by the US Constitution in Article 1, Sections 8 and 10. (see Appendix I). This may indicate that it wont be to hard for them to reintroduce the gold standard.
Commercial Banks do print money, about 80% is created by Commercial Banks, when they make laons to support other forms of asset creation like money market funds and commercial paper.