I believe the idea of using duct tape, is it was designed (as it's name suggests) to seal air leaks in duct joints. Masking tape does not have the strength nor adhesion required to do that. Of course in an emergency grab whatever you can find. Another thing with duct tape is it's versitility. I have even used it as a fan belt on my truck to get back out of the woods. It can lay around almost forever and still be somewhat usable--other tapes such as masking tend to dry out and become unusable. I keep several types of tape handy and usually try to use the one designed for the job but if I was limited to only one to perform for all, I would choose the duct tape. Just an opinion for what it's worth.