I'm putting a new 20 amp circuit in as part of a basement refinish project. I bought roles of 12 gauge black and 12 gauge white wire that looked identical on the shelf. As I started running it through the new conduit I'm putting in, I realized that the white was a lot more flexible. Come to find out, it is stranded while the black is solid.

Does this matter? They are both rated at 600 V - same manufacturer, etc. But the black says "ft-1 approved" and the white (stranded) says "vw-1 approved". I have never heard of these terms.

Since I've already cut into the rolls and probably can't return them I'd like to drive on. They both should carry current fine, and this will not be a heavily loaded circuit. But I just wanted to verify before I get much further on the job. I've been told never to mix gauges within a circuit...would using these together have the same effect?

Thanks!