I used left over crochet thread from when I was making doilies and bought the jumbo sizes, so wound up with a ton left over. I knit double stranded, and it came out very nice. The only problem is, the cotton stretches a bit, and knitting with the crochet thread always seems to create a tendency to lean or twist to one side, so the button strip likes to migrate over to the left and the sleeves kind of twist, each in the same direction. I noticed the same with a blouse I knit out of this same thread as well. So I just have to adjust it now and then to keep things straightened out.

And I love the glass buttons!! :D