Owner Russ said in an e-mail just today:
"I was just asked again about the kinds of wire. Here's the answer I gave and some links to more info about wire and metal
Hardness is the "temper" of the wire or how springy the wire is.
Dead soft is as soft and bendable as the wire can get.
Full hard is as stiff and springy as the wire can get.
Half hard is halfway in between.
Sterling wire is inherently softer than Gold Filled wire.
Wire temper can be changed by heating and controlled cooling or by bending, pounding, stretching, drawing or otherwise work hardening it. Heating wire to soldering or kiln temperatures and allowing it to cool in air will remove all temper - making it dead soft. The "softening" process is called annealing.
Half hard wire is used for wire wrapping and wire names where you want sharp bends to keep their shape. It is harder to use, requiring better tools and more hand strength. Soft wire is used for making loops around small beads and for general silversmithing. We sell much more dead soft wire than half hard. We do not carry full hard wire but can special order it. Most people find full hard too hard to use for wire wrapping. (Name artists are the exception.)
Brass or copper wire is typically used to "practice" wire wrapping techniques.
Here's some links to threads on Bead and Button forum with more comments about what wire to use where:
And some other links that will probably give more info that you wanted.
I hope that helps!!