You have many choices regarding what metals your jewelry making wire is made of, including precious metal wires and base metal wires. Options include solid metal wire, filled (overlay) wire, plated wire, enamel-coated colored wire, and anodized wire.
Solid Precious Metal Wire is the number one choice for high-end jewelry and craft designs. Options include .999 fine silver, .925 sterling silver, and Argentium® sterling silver wire. Argentium is a tarnish-resistant alloy, which means you and/or the end user will spend less time polishing!
Silver Fill & Gold Fill Wire are also called overlay. They're created by using heat and pressure to apply a thick layer of precious metal to a base of less costly metal. Use these when you're making upper-end designs but need something more economical than solid precious metal wire. Fill/overlay is typically considered precious metal, despite not being solid, because the precious metal surface is hundreds of times thicker than a plating
Solid Base Metal Wire works great for making finished artisan jewelry. It's also popular as a practice material and way to create prototypes for precious metal designs. Copper wire is especially popular for all 3 of these uses. Other options include stainless steel, nickel silver (aka German silver), brass, and bronze wire. Which base metal you choose will largely be based on what color you want for your design.
Antiqued Metals )patinas)-
A patina is a corrosion or oxidation that takes place on a metal surface. Rust on iron is one example; tarnish on silver is another. Patinas often form naturally by long exposure, but can also be created artificially for an antiqued (a.k.a. distressed) look.