The pattern is Anne's Magic Stripes (which really only has to do with the self-striping yarn) from Antje Gillingham's Knitting Circles Around Socks. From start to finish the directions were clear and easy to follow, although my friends and I all found that perhaps the measurements for the size we chose were a little off. I had to stop long before the recommended length for the foot.
The yarn is Premier Yarns' Serenity Sock Weight in the color Aquamarine, one of the many Iona-inspired yarns in my stash that I wrote about last spring. It's 50% merino superwash, 25% bamboo, and 25% nylon.
My socks are fraternal rather than identical twins, but that's okay with me - they're soft and warm and, best of all, finished! I've already cast my now trusty two circulars on for another pair, this time for my husband (but shhh, don't tell him yet!).
