fiberglass drywall Joint Tape 1. reinforcing wall surfaces in buildings 2. an ideal material for preventing wall cracks Fiberglass drywall tape is used for covering the joints between drywall panels. The major benefit of fiberglass drywall tape is how easy it is to install. Because it is self-adhesive, fiberglass drywall tape doesn't need to be embedded in a layer of joint compound, as paper ...