WDielectric
WBakelite
WBoPET
WCorona ring
WElectrical tape
WElectrical treeing
WFriction tape
WGlass
WHemingray Glass Company
WKapton
WLeyden jar
WLichtenberg figure
WMica
WNeoprene
WNylon
WPlasma pencil
WPlasma actuator
WPlastic
WPoly(methyl methacrylate)
WPolycarbonate
WPolyester
WPolyethylene
WPolyimide
WPolymethylpentene
WPolypropylene
WPolytetrafluoroethylene
WPolyvinyl chloride
WPorcelain
WQuartz
WRutilated quartz
WSapphire
WSlate
WSoapstone
WTitanium oxide
WYogo sapphire