This is so soft and warm compared to the Halo sleepacks that we have always bought.The fabric is a chenille on the outside with a woven cotton lining. I bought the large size for my 21 month old. She is 33 1/2 inches tall and should be able to wear this for another year. I would have given it a 5 star rating if only the velcro would have been sewed on better, one piece is coming up after only a few uses. I can sew it back on, so no problem but it should be sewn on better.