4 points
TIL!
That said, reading the Wikipedia article, there very much were tapes made for repairing ducts.
It was commonly used in construction to wrap air ducts.[20] Following this application, the name “duct tape” came into use in the 1950s, along with tape products that were colored silvery gray like tin ductwork. Specialized heat- and cold-resistant tapes were developed for heating and air-conditioning ducts. By 1960 a St. Louis, Missouri, HVAC company, Albert Arno, Inc., trademarked the name “Ductape” for their “flame-resistant” duct tape, capable of holding together at 350–400 °F (177–204 °C).[21]
