Hi Carolyn - sorry for the delay - I was hoping that someone who had woven with that particular blend of yarn would pop in with an answer. My answer is - it depends on the percentage of each fibre in the blend. If it has I high percentage of alpaca, then it has a good chance of fulling after taken off the loom. A high percentage of silk won’t give the same result. The best thing to do would be to weave a sample, full it and then decide if you would be happy with the result in a blanket.