- How coils were made before injected molded bobbins
- Preferred manufacturing method for high voltage application or where uncontrolled voltage spikes are common
- First layer of magnet wire is wound on a paper (Kraft, Nomex) tube; successive layers are separated by mica or Kraft paper
- High dielectric strength between winding layers
- Moisture resistance by vacuum varnish impregnating
- Qualified in nuclear industry
- Little or no tooling cost
