Hi Maggie,
I was also looking for it for the white trim on Fibre Craft's Little Red Riding Hood, and had no luck and I resorted to Lion Brand-Jiffy-Quick and Easy Mohair look yarn and it worked perfectly. You can find it at almost any yarn store like Hobby Lobby or Michaels, I've even seen Wal-mart carry it a time or two. Hope that helps!
Crystal