A can assembly includes a can body, and a cap that is seamed to the can body, and a bag. The bag, which may be formed by a thermoforming process, includes a thickened portion as part of a peripheral flange that terminates in a bulb. A throat that receives the bulb is formed by necks on the body and cap such that the bulb is spaced apart from the seam. A constriction formed by the neck radially inboard from the bulb receives the thickened portion of the bag. The process for forming the can assembly includes forming the seam and thermoforming a billet into the bag. At least part of the flange is formed between matched portions of mold flanges.