What is gold wire used for?
What is vermeil?
What is the difference between gold solder and gold wire?
There are a number of types of gold wire.
Gold-plated wire is copper or some other base metal coated with a thin plate of 10 to 14 kt gold. The plate easily comes off over time, can be scratched off, etc. so I wouldnt recommend using gold-plated wire.
Gold-filled wire is frequently used by jewelers and artisans. Gold-filled metal is made by pressure-bonding a layer of gold to a base metal core. Gold-fill usually has a copper base covered in thicker layer of gold, usually 14 kt. The gold does not easily get removed from the base. Jewelry made with gold-filled wire will look like new for a very long time and can be cleaned and polished without being damaged. This is the wire I use when I use gold in my designs.
What is Vermeil?
Vermeil is sterling silver which has been heavily gold plated. Gold vermeil by FTC standards has a 100 millionths of an inch layer of 14kt gold over sterling silver.
All wire described above can be used in jewelry making. Wire wrapping, making bead links, making clasps, you name it. If you can make it with silver or craft wire, you can use gold wire.
Gold solder is something different entirely. Gold solder is used in the soldering process. Gold solder does come in wire form, as well as sheet, but never use gold solder wire for anything other than soldering. Gold solder is much too soft, and is meant to only be used to fuse gold components of a piece of jewelry together.