The large and medium bags are made of Neoprene. They are machine washable, so no icky cleanup. The large bag/lunch tote is the perfect size for your kiddo's lunch. The middle bag is sized for those on-the-go cold snacks like baggies of grapes and carrots with a small ice pack. And the smallest bag/coinpurse fits all variety of little toys or crayons. They store flat when empty.