[TowerTalk] Best Wire for Radial Field

[Brian Maynard]

I am getting ready to put out a radial field for my 80M shunt-fed  
tower antenna.  I have not read anywhere what is the best type of  
wire or gauge for this project. I have a large spool of 18 ga.  
enameled wire at my disposal - but would stranded wire be best?  The  
"invisible-fence" wire at Home Depot is pretty cheap - looks like 7- 
strand 18 ga.

I would appreciate the collective advice.

Brian, K1NW