Hi, the yarn called for in the pattern is pure laine 3, 5 (available at http://www.breiweb.nl/). The pure laine has 108 meters or 118 yards per ball. I am using Elsebeth Lavold Silky Tweed, which has 131 yards per hank, so I need 11 hanks for the second smallest size. Sadly I only had a bag of 10 in my stash so I ordered a skein of a different dye lot and am hoping for the best. I purchased my yarn on eBay a while ago, and it is still easy to find there for about $5.50 to $7.50 a hank. Silky tweed is a really nice yarn, it is 8 ply with a subtle sheen and is incredibly soft. I don't think the picture really does it justice. I got gauge using US 4's for my Godron Stitch swatch.