*static* Wood and photons. I don't think wood would be a good insilator. It is light weight though.
The shape of the hilt helps, too. I mean, seriously, who'd try and grab a Saber by the blade? The design ensures that the hand holding the weapon can't slip over the blade by accident. Also, it would make sense if Shieldlines guaranteed protection from weapons owned by you.
But how would the Shieldlines know? If you're using a mass-produced weapon, surely they all have the same output, so the line wouldn't be able to tell.