Made from 100% cotton fleece. Skinny flats are so versatile and can be customized to get the trimmest fit. Newborns need to be changed much more frequently and flats are a great option for daytime and nighttime use. You will likely need boosters with flats as baby's output increases. Covers are needed for fully absorbant nappies. NOTE (For Newborn) These prefolds/flats generally require boosting as output increases so would highly recommend buying an additional newborn size insert.