Poly-coated wire is the modern standard; consistent coating gives a cleaner, more uniform sound in similar pickups with the same number of windings.
Each 1/2-pound roll has over 25,000 feet of wire, enough to wind 5-6 single-coil pickups, or 2-3 humbuckers.
"On most pickups, I use poly-coated coil wire for its consistency, durability and overall clear sound."
—Erick Coleman, repairman and StewMac tech advisor
42 AWG (American Wire Gauge) is the standard wire used in humbuckers, Strat® pickups, and Tele® bridge pickups.
43 AWG is used at the Tele neck position and in Rickenbacker pickups. 43-gauge wire requires fewer windings to attain a desired coil resistance.