Press and seal liners are as simple as their name implies. First, you must remove the lid or closure from the container you wish to use the liner in. Make sure the rim of the container is clean. Then, place the press and seal liner in the roof of the lid you removed. Make sure the correct side is facing up (usually the side with text should face the customer). Next, screw the lid back onto the container. It will take at least 45 minutes for the liner to stick, so do not move or manipulate the lid.