Abstract: The present invention relates to a system for sealing a cover onto a container. This system includes a die comprising a surface into which is formed a container receiving cavity and a groove. The system also includes a seal comprising a groove insert member comprising a body and a neck formed at one end of the body and a contact member comprising a first end and side walls extending to a second end, where the contact member is connected to the neck at the first end, the first end being wider than the neck to form two opposing edges that extend laterally from the neck, where the groove insert member is removably seated in the groove so that the two opposing edges rest on the surface to seal the groove. Also disclosed is a seal and a method of sealing a cover onto a container.