I don't know the actual ingredients of the 80s Cinelli cork tape, but it appeared to be at least mostly cork (51%??) mixed into some sort of substrate to hold it together. It felt pretty corky, for lack of a better word. I guess the idea of cork tape has steadily been diluted, literally.

The Duck tape above seems to be the usual shelf liner / bulletin board type composite cork: mostly ground up cork and not much goop to hold it together. Good luck getting it around a handlebar without breaking it. It might be possible if one was really really careful.