This composite waterproofing tape, manufactured for use in the insulation of blind frames under windows, consists of a polyethylene carrier layer with a special polyester felt protection on both sides. The fibrous structure on both sides provides strong adhesion to all surfaces and allows for the application of various coating materials. Our tapes, which can be applied with self-adhesive or special acrylic-based adhesives to prevent water-heat-air transfer around window edges, can be produced in custom sizes according to user requirements.