during the deep drawing of a cup - shaped container from a plastic sheet , its wall is surrounded by a sleeve of cardboard material or the like which reinforces and insulates the container and can be used to carry decorations . the upper and lower edges of the sleeve are enclosed by radial protrusions of the plastic of the container so that they cannot come into contact with the moisture of a base surface . positive engagement between sleeve and container is ensured and the sleeve supports the wall which can be made very thin .