My reading of the TN indicated that if you want to comply with the TN you need a positive air seal on the hinge side so mylar seals will also need a sealing tape attached to both the control and the fixed surface beneath the mylar on the hinge side. For our club Grobs we decided to use the Tesa fabric tape on the hinge side and nothing else because the shop that does our annuals insists on lubricating the hinges every year. This means the seal has to come off every year and I'm not about to spend the time energy and money to redo a full set of tape, double sided tape, mylar and teflon tape seals every year. Our experience was that simple mylar top and bottom worked fine but when the TC holder issues a TN regarding approved seals that includes the phrase "to prevent flutter"...