After lamination or coating, we can cut the material to the width you want. We then call this a seam tape. Sewing creates small perforations in the seam. To make the seam watertight, the seam can be sealed afterwards with a seam tape. The tapes have a thermoplastic adhesive layer on one side. When exposed to heat, this melts and by applying additional pressure, the adhesive closes the seam and the tape adheres to the fabric.