What does quadruple silver mean when it is on a vase?

Answer 1

Any precious metal, whether silver or gold, is deposited on a base metal core. The depth of the plating, which is is done via a process known as electro-plating is measured in microns. So, the outer skin of precious metal which is deposted can vary depending upon the length of time the object is left in the plating tank. This is determined by the customer. "Quadruple silver" is not a finite measurement of the depth of the silver plate. But, it was a simply marketing tool which implied that the depth of the plating was thicker than normal.