Most people who use the size 8 do the blanket stitch by hand. The size 30 in a Perle cotton might be a better choice. I used a 40 weight sewing thread when I did a blanket stitch on some applique and really didn't like my results. Next time I am going to try the Perle 30 or any 30 weight crochet thread...not necessarily that specific brand. I am not a hand sewer, although I really like the results.