Gold-filled (sometimes called gold
overlay) is made by bonding a layer of gold to a brass core
through heat and pressure. This produces a surface with
karat gold. The minimum layer of karat gold must equal at
least 1/20 of the total weight of the item. Tubing is usually
seamless, so that only gold touches the body.
The surface layer of karat gold is usually
10kt, 12kt or 14kt. Also, to know the thickness of the layer,
look for a fraction, such as 1/10 or 1/20. It is usually
1/20, unless otherwise stamped. Examples:
1/10 10kt GF: 1/10 of the total weight must be 10kt gold.
1/20 12kt GF: 1/20 of the total weight must be 12kt gold.
The gold-filled wire I use is 14/20, which
means that 1/20th of the total weight is 14k gold. This
is a much thicker layer of gold than any plated material,
and has a higher gold content than 10 or 12k gold-filled
material. It is a lifetime product for most people. |