Hi, cverny I would be interested too to be kept in the loop of whatever conductive filament you come up with. Solderable would be insanely interesting but high conductivity would be a great start.

@Wolfie : tritium is mostly dangerous when gaseous (radioactive stuff in your lungs is a definite no go). The problem is also that tritium by itself is not light-emitting. It is the gamma rays hitting phosphorus that actually emit light. So you need a process that ensures the proper amount of both in close vicinity. I'm guessing filament containing tritium is not for tommorrow... on sale. With desktop filament extruders however, nothing stops you from experimenting. Buy a vial or too and drop them in the vat when extruding filament. Don't misunderstand me though : I still think it is a very bad and very dangerous idea to try at home.