High Quality Content by WIKIPEDIA articles! A bin bag, swag sack or bin liner (British English) or garbage bag, trash bag, refuse sack, black sack, or can liner (American English) is a disposable bag used to contain rubbish. Such bags are useful to line the insides of waste containers to prevent the insides of the receptacle from becoming coated in waste material. Most bags these days are made out of plastic, and are typically green or black in colour.