What is Gold filled?

Gold and Swarovski Flower Brooch

I thought I'd take a little break from my usual posts and tell you a little about some of the metals I use in my jewelry. Gold filled is one of the metals I use, usually yellow 14 karat gold filled wire and components. This is an excerpt from Otto Frei's website:
Yellow Gold Filled and White Gold Filled are man made metal products produced in the United States. They are vastly superior to any kind of gold plated product, making for a longer lasting and durable jewelry product.
Simply put, a layer of solid gold, either 12K (50% pure gold) gold or 14K (.585% pure gold) but at least 10K (.417% pure gold) is mechanically bonded with heat to a thicker piece of base metal. The gold layer is fused to the base metal, resulting in a product that has all the beauty of its actual karat gold plus long lasting resistance to wear.  The finished product must be by weight 1/20 (5%) solid 12K or 14K gold by weight or in the case of 10K GF, 1/10 (10%) solid 10K.  This process was invented in the United States and used extensively in the manufacture of pocket watch cases, many of which are still gleaming bright a hundred years after they rolled off the production line. (continued below)

   

 Simple Arrow Leaf Earrings in Gold

Gold Filled mill product is made in a variety of flat sheet and wire shapes and sizes. The stock products are used by large findings and chain manufactures using specialized equipment to create finished products.  Otto Frei sells 1/20 12K Yellow Gold Filled wire in even number wire gauges form 16 to 24 by the half ounce package. Because this is raw material, it is not required by law to be stamped 1/20 12K, as such markings can only be made after a piece is fabricated.  We also sell a wide variety of YGF and WGF findings including many styles of YGF bulk and finished chain. 

WGF product will usually always be Rhodium plated, as the beautiful yellow of pure gold will always want to show through a white gold alloy, no matter how much Nickel or Silver is added to pure gold to make it appear white.  

Rolled Gold or Rolled Gold Plate is similar to Gold Filled, but have far less gold by weight, usually around 1/60 12K by weight.

When I make my jewelry, I use 14 karat gold filled wire and components whenever possible. It is much more expensive than gold plate, but the gold will last for years with gold filled, versus months or weeks or days with gold plate. In the case of jewelry, you really do get what you pay for :)