I think it's pretty remarkable that you can buy sub-micron thick films of pure gold, many other pure metals (see the Sample Group link below for the list) and countless mixtures and alloys thereof, off the street in any major city, and you've been able to do so for several thousand years. Leaf like this is so thin it has to be picked up with special Red Squirrel hair brushes (none of that Gray Squirrel crap, mind you) and when it wafts down onto an object it conforms to the shape of the surface, settling in even to details as fine as a fingerprint.
I bought this leaf from a store in New York when I was visiting there with my six-year-old daughter Addie: You can read about our visit here.
Source: New York Central Art Supply
Contributor: Theodore Gray
Acquired: 11 July, 2003
Price: $37/25 sheets
Sample Group: Metal leaf