Starting with AlNiCo 5 rod magnets, the bobbins are lacquer dipped in nitrocellulose like was done back in the day. This adds strength and some insulation on the conductive poles.
Of course, the magnet choice is a suggestion. You may decide you want a unique mix of different strengths (A2, A3 and A5).
42 gauge wire is used to on both coils. The cover for the bridge is 8 strand cotton string. This is what was used in the early days of the Telecaster. Finally, the bridge coil is very lightly potted in paraffin/beeswax with lampblack for the same look as years ago. Despite the high inductance (true output) of these pickups, the clarity is all there due to the scatter wind reduction in stray capacitance.
Remember : resonant freq = 1/ 2pi * sqr rt of (C * L) C is stray capacitance and L is inductance.
Raise either of these and the resonant frequency goes down…along with your tone.
These pickups are wound to a high resonant frequency for true and unmistakable clarity.
Just winding to a known inductance value is not enough. If stray capacitance is too high, tone is lost. To a degree, hand winding (scatter winding) can increase or decrease the resulting stray capacitance. This is what allows the highest frequencies to go to ground. As a result, part of each coils testing includes a Bode plot on an oscilloscope to validate the coils consistency.