41 gauge wire/.0028″

This is a noticeably thicker wire. It will more quickly build up a coil needing fewer turns. This wire has a tendency to sound wide and has a lot of treble. Its tough to get even a moderate output without changing the bobbin size to accommodate more wire. I think this is a great wire choice for winding low impedance pickups.

42 gauge wire/.0025″
The thicker the wire, the more quickly one can build up the thickness of the coil you’re winding. This wire has a tendency to sound (“Right” or “Classic”) A very familiar and even blend of treble to bass. Tends to yield a low to moderate output rating.

43 gauge wire/.0022″
This wire type is of the smaller variety. A smaller wire allows the winder to fit more turns on a bobbin and thereby create a hotter pick up while occupying the same amount of available space. This is the type of wire one uses to get a higher output humbucker or single coil. Sometimes this wire gauge is used in foil type pickups.

44 Gauge wire/.0020″
This wire, much like the 43AWG wire, is very small. Smaller wires allow for more turns to fit on a defined space. This wire is well suited for getting a “Normal” output reading from a pickup with limited space available. Very small and or foil pick ups.