A container closure is comprised of a closure member molded on a liner, the liner having a first surface secured to the closure member and a second surface opposite the first surface and including a member depending therefrom and configured both for effecting sealing of a container and for releasable securement of the liner to a forming member in the course of such molding of the closure member thereon. The closure member and liner materials may thus be diverse, since they are separately formed. While there are separate manufacturing steps for making the liner and the closure member, the customary step of assembling preformed liners with preformed closure members to obtain desired performance diversity therebetween is eliminated.