It's 100% cotton. There aren't any noticeable milk stains or pilling, but it does have a worn feel from repeated wear. However, as you'd expect from Uniqlo, it's durable even after repeated wear and held up well in the dryer. I received this as a hand-me-down, and I really liked wearing it. Since I don't have anyone to pass it on to, I'd be happy if someone else could use it. I've checked everything thoroughly and will note any major damage, but there's a possibility I might miss something small. Please understand that this is a child's hand-me-down, and I hope that those who don't mind minor imperfections will purchase it. I don't have any pets, and I don't smoke. If you'd like measurements, please comment. I'm also selling other children's clothes and items. I offer a discount for multiple purchases, so please use the combined purchase function or comment before buying! Since this item is still wearable, I'd be very happy to pass it on and have it be put to good use. I will do my best to ensure a smooth transaction, so thank you for your understanding. 【Regarding Baby Clothes Names】 The definition of baby clothes names is vague, and I've listed various names, but I hope you will judge the exact shape from the photos. Search terms: Rompers, coveralls, pre-alls Boys, girls, girl, boy