That black stuff starting to creep over your shiny silver-plate teapot isn't mold; it's tarnish, and just as sterling silver tarnishes, so does silver-plate. All silver reacts to chemicals in the air, especially sulfur, and that's what brings on the tarnish. Just because it's silver-plate doesn't mean that it's resistant to tarnish. The intensity of the tarnish buildup is directly related to the amount of use the piece gets. Silver jewelry worn often rarely requires tarnish removal. Tableware stored unprotected in a cupboard and brought out only for special occasions will definitely need cleaning.
What Is Silver-Plate?
If it looks like silver, it is, or is it? Sterling silver, composed of a minimum of 92.5 percent silver, is silver throughout. When layers of silver are electroplated over a copper or brass base, it becomes silver-plate. The plating is thin and susceptible to damage from over-zealous cleaning. Silver-plated pieces don't carry a mark like sterling silver does, which is a good way of verifying the quality of any piece.
Tarnish Has No Favorites
A chemical reaction takes place when silver alloy meets sulfur-infused air. The salt from body sweat; contaminated air as a result of industrialization, such as heavy smog and the burning of fossil fuels; and dampness in the air -- all affect the silver surface, whether it's sterling or plate. The dull yellow-gold or deep black buildup working its way over the silver surface is tarnish, and the sooner it's removed, the longer your piece will survive to shine another day.
Taking on the Tarnish
Liquids, pastes, and aluminum plates and foil remove tarnish buildup on silver, but they can damage silver-plate. The method you choose has a direct affect on the longevity of the silver; some of these methods remove layers of silver, and others gently wipe the tarnish away without causing damage. Don't submerge the silver-plate in a baking soda bath as it'll eat away the silver and expose the under-metal. Extensive abrasive cleaning results in the silver getting scoured away to reveal the copper or brass base metal underneath it.
A warm water bath with a non-phosphorus and acid-free dishwashing liquid should chase away the tarnish on silver-plate. Dry completely with a microfiber or cotton towel before storing.
A silver-polishing cloth that's been treated with a sulfur-absorbent is another safe way to restore the shine on silver-plate. Be sure it's clean or new. Don't spread the tarnish around by over-using the same spot on the cloth; wipe the item clean with a towel.
Avoid using cleansers designed for other metals. They're harsh on the silver-plate and can cause damage.
Silver and silver-plate should be stored in an air-free environment to prevent the buildup of tarnish. Drawers lined in sulfur-absorbent fabric are designed especially for all silver. Felt silver pouches keep the pieces tightly wrapped and protected from air.
Don't store the silver-plate in any protein-based fabric such as leather, wool or silk as they contain sulfur-compounds and create tarnish when exposed to silver.