Selecting the most appropriate bonsai wire will make a lot of big difference to your bonsai. Generally wires used for bonsai tree wiring is made of Aluminum or Copper. The two types have their own advantage and disadvantage. Copper mineral and Aluminum are incredibly ductile and can be easily bent, can make them perfect material for bonsai cable. hot dip galvanized wire
There is a refined difference between wires produced from copper and those made from aluminum. The real estate agent wires once bent usually tend to harden and are difficult to change their condition again, where as aluminum wires are can be reused pretty easily. Explained this though, annealed copper are pretty adjustable to reshaping and can be reused more often than once.
In the event you are a newbie then how to use aluminum wire rather than a copper wire, another good thing about using aluminum wires is the fact it is cheaper and does not oxidize when exposed to heat; this is more secure for some plant types. One problem with using aluminum bonsai wire is usually that the glaze on the line might be a frenzymadness, desperation, hysteria, mania, insanity, delirium, derangement for the viewers, to overcome this drawback use an anodized aluminum materials wire. Compared to light weight aluminum bonsai wires copper wiring are dull in there color and are relatively stiff. Therefore it is generally preferred by experts who have experience in wiring. One more good practice is to oxidize the copper cable before using it. This kind of will make it safe for the plants as well.
The standard gauge of the wires used for bonsai cover anything from 1mmm to 6mm. One of the accepted guidelines for the thickness of the branches is that the thickness of the wire should be around 1/3rd the thickness of the branch to be wired. For very think tree trunks you should use double strand of wire, so that the trunk stays in it is new condition after wiring.
While removing the cables from your bonsai always use a wire cutter machine to cut through rather than trying to unwind it from the tree.