Okay, you're reaction is probably the same as ours was intially when 3M approached us with this duct tape. "$50.00 for a roll of duct tape, are you crazy!!"
Turns out they were crazy like a fox! This is, hand's down, the greatest duct tape we have ever used for our glass work. We've used it to hold together pieces in the Rociprolap while they polish in cerium slurry and water for 10 hours. It never even loosened even after being soaked for 10 hours. How's that for protection! We're able to strap together several pieces in the Rociprolap now and now worry about them seperating because our tape got too wet and lost it's adhesion. This stuff doesn't lose adhesion in water.
We've used this tape on all of our smaller pieces or on our hemisphere's and lenses when we're grinding them on the flat lap or belt sander. We make little handles out of the tape that we stick to the glass and they hold the whole time we're working the glass. No more crimped fingers, no more grinding off our fingernails or friction burning off our fingertips. The 3M 393 cloth duct tape makes it possible for us to more efficiently work our glass from hand grinding to automated grinding and polishing.
We think you'll be impressed as well.