This art has become very popular in Latin america.  It is done with foil, but also silver-foil, gold-foil, copper foil and also tin.

It is basically pushing against the back of the material to form shapes, faces, landscapes, you name it.  It can be mixed with wood to highlight it or attached to boxes or frames.

There is a similar craft we do with paper, called parchment crafting or Tarjeteria Española. 

• Russian Metal Embossing Samples and galleries on the web