In response to your inquiry, mylar isnot a tape it is a plastic material that I had on hand and used, it is non conductive and is available in so many places and you probably have it in your house. Have you ever bought a pack of batteries or any other product with that annoying plastic -see through material that you had to tear to get at the product? Just make sure that it is not to thick, but thick enough for the flex cable and that plastic can fit within the connector, This slides on top of the flex cable if the contacts are facing down once you trim the plastic to the flex cable dimensions. The electrical tape holds this in place!
Joe Collins