I have used Hobb's wool, which is very light weight, and Matilda's Own, which is much heavier, very warm and a dream to quilt. what I am using these days, however, is Thermore, a very easy to use dense, thin poly, and somewhat cheaper. I don't think Hobb's wool is any warmer than a good cotton poly blend. I have machine washed and dried my own Matilda's quilt on a delicate setting, which is what I generally use anyway.One of the people I gave a baby quilt to just washes it with the regular laundry.