There is provided a cap liner including a fluid impermeable layer for venting gas to and from the container and an adhering device for adhering the impermeable layer to a rim of a container and a channel extending therethrough for venting gas therethrough. Also provided by the present invention is a method of sealing an opening of a container by affixing a meltable layer of a sealing member to a container rim and venting the container through a vent patch, meltable layer, a foil layer, and a fluid impermeable layer having pathways thereon.