what is the envelope of a hot air balloon made of
Hot air balloon Modern hot air balloons are usually made of materials such as ripstop nylon or dacron (a polyester).[19]
Duct tape After the war, the duck tape product was sold in hardware stores for household repairs. The Melvin A. Anderson Company of Cleveland, Ohio, acquired the rights to the tape in 1950.[15] It was commonly used in construction to wrap air ducts.[19] 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]