After Saturday's post, I grabbed that Dorchester Farms superwash sock yarn from the yarn box (yes, although I previously declared an aversion to sock knitting, I did have some sock yarn on hand), and began a test swatch.  Unlike Cassie, I get a tiny bit obsessive about gauge.

Hey, that's pretty good.  I'm using the Sugar Scallops edging from Knitted Embellishments.

This swatch tells me two things.  One, I love the way that this sock yarn is striping!  Two, if I want to use the Sugar Scallops edging, I will need to cast on extra stitches, knit the edging in a bigger needle, and then switch to US3s when I begin the sock cuff.  The edging loses stitches as it's knit, and the last row involves knitting five times into the same stitch--resulting in some very tight stitches.  I'll try it in a US5, and see if that solves the problem.