When storing new or partially used wire spools, they should not be stored with the wire laying horizontally (laying on the spool flanges). It is common to store a spool by laying it on the flanges so that the spool does not roll away; however, this can loosen the wire on the spool or cause the wire to unwrap and become looped underneath itself.
If the wire becomes looped underneath itself, it can be very difficult to spot. This can cause machining performance to suffer, most likley with multiple wire breaks. It is recommended that wire be stored vertically in its original box or by using a standard industrial bin, such as Akro-Mils® AkroBins #30240, which is stackable and rackable. Stored wire should also not be exposed to the open shop environment where dirt or oil can contaminate the wire.
Simply by taking a little extra care and caution with storing wire spools, you’ll reduce chances of wire breakage and poor machining performance; potentially saving yourself a ton of frustration in the process.