Carbon is non conductive and very leight weight.

Graphite is 'activated' Carbon and has resistive properties .

Graphene is a single layer of Graphite treated in a way that the structure becomes highly conductive depending how well it is treated.

So depending what you want to do you need to figure out what form of carbon you are dealing with.

And how it is combined with PLA ABS or other plastics also has influence

A few video's that shed some light on pure Graphene: