Duct tape is normally made with plastic (vinyl), cloth strands (cotton), and adhesive.Does anyone know if duck brand duct tape metallic??
It is not magnetic and not metallic BUT, it is unclear if the prohibition on metallic tape is intended prevent duct tape from being used.
The only truely metallic tape I am aware of is used for heater ducts (hence the confusion) but is actually called muffler tape.
Maybe you should submit a clarification if you plan to use duct tape so you can find out the intent