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 up to four 4oz bottles, perfect for the back and forth to daycare. 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/coin purse fits two pacifiers. Keep them clean while you are out and about. And they store flat when empty. The dye sublimation printing process creates slight imperfections that are unique to each item.