RED HEART strata is a knit yarn that features fine fibers knitted into a tube around a soft core. This is similar to a traditional T-shirt yarn but the tube structure means that it will not fray and edges will not curl. This is size 5 bulky worsted and a 76percent acrylic, 24percent nylon extremely soft yarn that has a little stretch to it. This yarn is perfect for making accessories, fashion items and home decor. We recommend a size us 11 knitting needle and a size l-11 crochet hook. Machine wash cold, gentle cycle. Tumble dry low, do not bleach, do not iron.