Last Updated on Wednesday, 14 April 2010 15:23 Written by GoldSmithWatchWorks Wednesday, 14 April 2010 15:19

What is the difference between RGP, WGF, YGF, EP and SS

1) 10KRGP/14KRGP/10RGP/14RGP/RGP/R.G.P. = Rolled Gold Plate

ROLLED GOLD PLATE is a  thin sheet of   white or yellow Karat (10/14 are the norm) Gold is fused with heat and pressure to a sheet of base metal such as brass, white metal or an alloy of several base metals.  The sheet is the put through a rolling mill to flatten the combined metals into a sheet and then the cases are stamped from this sheet. ROLLED GOLD PLATE is the best  form of gold finish when an item is not KARAT GOLD..

2) Gold Filled/WGF/YGF/GF/10GF/14GF = Gold Filled

Thgough also known as "rolled gold" or "rolled gold plate", Gold Filled items are composed of a solid layer of gold bonded with heat and pressure to a base metal such as brass. Yet there are different processes utilized to bond the gold to the base metal and not all gold filled items are run through a rolling mill.  In most cases a heat process is utilized to apply the karat gold directly to the base metal.

In the USA the quality of gold filled is defined by the Federal Trade Commission.

If the gold layer is 10 kt fineness the minimum layer of karat gold in an item stamped GF must equal at least 1/10 the weight of the total item.

If the gold layer is 12 kt or higher the minimum layer of karat gold in an item stamped GF must equal at least 1/20 the weight of the total item.

1/20 12kt GF and 1/20 14kt GF are the most common stamps found on gold-filled jewelry.

1/10 10kt is also common.

Some products are made using sterling silver as the base, although this is the best and most expensive version found in vintage items and is not common today.

3) "Double clad" gold-filled

A sheet is produced with 1/2 the thickness of gold on each side.

1/20 14Kt double clad gold-filled has a layer on each side of 1/40th 14Kt making the total content of gold 1/20.

The thinner layer on each side does not wear as well as single clad gold-filled.

The Federal Trade Commission allows the use of "Rolled Gold Plate" or "R.G.P". on items with lower thicknesses of gold than are required for "gold-filled."

1/60 12kt RGP designates a 12 kt gold layer that is 1/60 the weight of the total item. This lower quality does not wear as well as gold-filled items.

4) GOLD PLATED/10KGP/14KGP/Gold Plated/EP/HGE/HGP (heavy gold plate)

Gold plating is a method of depositing a thin layer of gold onto the surface of another metal, most often copper, silver or a base metal alloy plated with copper then gold by chemical or electrochemical means. 10K-14K-18K GP or EP or KP refers to Specific Karat Golod & Electroplating.

There are also some watch bands and cases that are simply stamped Gold Plated w/o a specific Karat Stamp

The actual specific thickness of the Gold Layer on gold-plated jewelry varies greatly depending on manufacturer & specific method such as:.

1. Alkaline gold cyanide, for gold and gold alloy plating
2. Neutral gold cyanide, for high-purity plating
3. Acid gold plating for bright hard gold and gold alloy plating
4. Non-cyanide, generally sulfite-based for gold and gold alloy plating

Many cases are stamped 10 Microns, (GSW plates HGE/HGP up to 40 microns ).

The use of sub-layers of  copper and /or nickle contribute to longer lasting plate

Gold plating of silver is used in the manufacture of  some watch cases such as the Must de Cartier. It is better to plated copper over silver and then the gold plating.

Copper and Silver atoms diffuse/migrate into the gold layer, causing slow gradual fading of its colour and eventually causing tarnishing of the surface. This process may take months and even years, depending on the thickness of the gold layer. In quaility plated items, a barrier metal layer of Nickle is used to counter this effect.

Plated items with a base layer of Copper, then Nickel, then a slow process of ELECTROPLATING is the best type of plating. If one does a slow process similar to ELECTROFORMING, the finished plated item will last 4 times as long as simple 30 second 10 micron gold plating

5) SS is Stainless Steel –

6) Silver = PURE SILVER

7) 800 = 80 parts silver 20 copper

8) Sterling Silver = 92.5 percent silver and the balance copper.