Interconnects: solid or hollow core wire?

So who all makes solid core interconnects?

i believe tara labs has a line of rectangular solid core interconnects. call them to see if they are still in production.

or you can google "solid core interconnect" and see if a name of a company is listed.

i did a google search and confirmed two sources of solid core cable:

1) tara labs

2) parts connexion--legenburg cable

Tempo Electric - Joe Levy. Single solid core pure silver. I use his IC from pre to amps, and SC.

Except for some flexible stuff for in-wall or something, I think Audioquest is all solid core.