Just checked the Weaving Today website and the webinar is now available for recorded 'viewing' here.
I will be giving this topic as a mini-workshop (3 hours) with some hand's on examination of various yarns at the Rochester, NY guild in October. If you want to attend, I have contact info - I heard they were still accepting registrations. I am also doing this topic as the guild program for my local guild next week.
Currently reading Dark Moon Defender by Sharon Shinn