More trivia: It was originally called duck tape not duct tape because water rolled off its plastic coating like water off a ducks back. When it was introduced the alternatives were cloth tapes that were not water proof. So it should always be duck tape, even if one company has laid legal claim to that name. It’s kind of the reverse of the Band-Aid and Kleenex situation.

I agree that if you are buying duct tape (for ducting), do your research, and buy the good stuff(quality metal foil HVAC tape in 99%of cases), clean the surface, and remember to spend a little bit of time rubbing it to the surface. Tape adhesive is a PSA. Pressure Sensitive Adhesive sticks better the more pressure you put on it.