I have barely worked with Insulbrite, so I'm not sure. I would use one layer of Insulbrite and one layer of batting. I recently used just one layer of Insulbrite in a hot pad and it seems stiff. Two layers wouldn't be very pliable for a oven mitt. I like my oven mitts to be usuable on both sides. I'm left handed, but my children who sometimes cook with me are right handed.