These bodysuits are 100% very soft cotton. I love the double row of snaps; it's smart. My daughter is 5 and 1/2 months old and she has been wearing size 6-9 m since she turned 4 months. A part from Disney's products. At least for what concerns my little lady, Disney's size is true. She is currently still wearing size 3-6 m! I am only disappointed that they don't make them in size 12 m and up... I totally recommend this product!