Haha, sooo I'd like to tell you a story.
Last Kumoricon I was cosplaying a Victreebel Gijinka, causing me to be busty and stuff. I taped my boobs together to get maximum cleavage. Later on in the day I decided to redo my cleavage tape so I took it off...
And I ripped all the god damn skin off sides of my boobs
That was just sports tape, I'd hate to think of what would happen with duct tape. I've heard horror stories of people ripping off layers of skin so it bled and like passing out from the paint. It'd be better to use fashion tape or something that like...is meant to be on skin. Having your boobs leak blood and other fluids into your bra for a week after con isn't awesome in the least let me tell ya.