A cloth that's roughly eighteen inches by eighteen, and is made of a light absorbent cloth called muslin, kinda like cheesecloth. I have lots of them, you basically hold them under the baby's chin when you are burping them and it catches the spew -up. My mother used them before me, I find them invaluable as they cover much more than a bib and are very washable and tumble dry.
Some people used old terry nappies!
Oh and one of the nurses in the hospital called them muslims too and said they were great for wrapping the turkey in a bit of muslim! I could only imagine this fiercely indignant ayatollah being wrapped around a turkey!
Oh dear....that's a joke folks, not meant to be offensive, so please don't take it as such.
Sue