Annealed in Japan for use by bonsai professionals.
The stronger holding power of copper is due to "work hardening." The more annealed copper is handled, the stiffer it will become. Store it preferably in a box or on the floor and do not re-spool it onto a reel.
Select from these quality wire cutters, however ensure you use the appropriate cutter for the thickness of wire being cut or the tool will be damaged.
Please handle annealed copper wire as little as possible prior to use.