Sterling silver is an alloy of silver containing 92.5% by mass of silver and 7.5% by mass of other metals, usually copper. The sterling silver standard has a minimum millesimal fineness of 925. It comes in different thicknesses. I tend to stamp with 20 Gauge, but it depends on the item. If it is a larger piece I may stamp on a higher (thinner gauge) to reduce weight on the neck and price.
Fine silver is 99.9% pure and is generally too soft for producing functional objects; therefore, the silver is usually alloyed with copper to give it strength while preserving the ductility and beauty of the precious metal. I don’t stamp fine silver.
Silver Filled is hundreds of times thicker and more durable than Silver Plated. It is a thick layer of .925 Sterling Silver mechanically bonded to copper. Silver Filled is 1/10 or 10% by silver weight. Anyone who can wear Sterling Silver can wear Silver Filled without an allergic reaction.
Gold filled is an actual layer of gold-pressure bonded to another metal. It is not gold plated as gold filled contains more gold than gold plated. It is brass or copper, covered by sheets of gold in a mechanical bonding process. It is much more valuable and tarnish resistant than gold plated. Gold filled does not flake off, rub off or turn colours. Anyone who can wear gold, can wear gold filled without worry of allergic reaction. Gold filled will last as long as 14K gold.
Rose Gold filled
Nickel silver is a metal alloy of copper, nickel and zinc.
It is named for its silvery appearance, and contains no elemental silver.
It can be stamped, polished and soldered just like Sterling or Copper.
It is harder than Sterling