Nappy liners do a very important job.... they catch poo! You can choose from disposable or washable liners. Disposable nappy liners make real nappies super easy making removing poo from your nappies a breeze. Disposable liners are made from biodegradable materials such as bamboo viscous, cornstarch or wood pulp. Washable liners are also very popular, fleece liners can be used as a stay dry layer to keep your baby's bum dry.