the present invention is a method and apparatus for attaching a soft plastic liner within an aerosol can and other cans such as flat top cans . the bag is attached in the can by the method of entrapment , or retention . the liner is typically a thin film plastic material with a thickened bead at the open end . the liner can be made of a polyvinylchloride material or a slightly more rigid plastic than pvc . when the dome and body are assembled , there is a cavity or pocket formed , as well as a narrow passage at the bottom of the dome . the thickened bead is entrapped in the cavity and can not pass through the narrow passage , which provides the correct space for the thin film bag . the aerosol can typically includes a bottom end and an opposing top end , the opposing top end configured to receive a valve dome , a liner comprising an open end , a closed end , a liner body disposed therebetween , wherein the open end includes a sealing bead which is thicker than the liner body and wherein said liner is disposed in said aerosol can , and a valve dome .