Single and double bubble are both made the same. The main difference is that single bubble foil has only one layer of polyethylene bubble between the two exterior layers of highly reflective aluminum foil. Both have the same effectiveness, blocking heat transfer through radiation. Double bubble is a stiffer product, which allows for easier installation. When compared with single bubble, it also provides better thermal break for reduced conductive heat (gain or loss) in buildings. Single bubble insulation is a cost-effective way to keep your building cool in the summer and warm in the winter. Single bubble is an 1/8” thick single layer of bubble insulation primarily used in warm climates. Single bubble insulation is a more economical & cost-effective choice if condensation is not a primary concern. For more information on the different types of bubble insulation and its uses, please see our website on Bubble Insulation.