Never even occurred to me until just now that variegated in top & bobbin will almost never match up so there's no need to use the same thread in both. Obviously, that means that I've only used the same variegated in top & bobbin. So far it's turned out nicely. I'm about to quilt another quilt with Bari variegated by Aurifil. Guess I'll have to pay more attention to how it turns out.