Anna - we use the long sleeved bibs from Sainsburys TU which are about £3 each, they're made of towelling type material. At lunch time I use it inside out so the plasticy backing is facing outwards so I can just wipe it after a meal, then for dinner I can turn it the right way and she is covered again. Then just either rinse it if it's not too covered, or put it in the wash, and use a different one the next day. I've got 3 of them, so used in rotation I don't have to do anymore washing than usual and always have one on hand...