They recommend shielded wiring. I purchaced 6 conductor plus groung plus a shielding wrap on E-Bay for a reasonable price. Do a search for stepper wiring or something like that. I see some people use nonshielded cable. There are enough hurdles to have a cnc work properly. I wouldn't start by intentionally
using parts that can easily create problems. I think I paid about $13 for 40'
of shielded. This is my first cnc project and my table always works with no surprises. I've learned to trust it.
Also I think it's 18 0r 20 ga......each conductor has 7 strands.