For most people, blanket insulation is the insulation that comes to mind when they think about insulation in a home. Most of us have seen attics filled with pink or yellow insulation. That pillowy insulation that we’re familiar with is blanket insulation and in most cases it was made of fiberglass, which is the most common type of insulation in the United States. But blanket insulation can be made not only of fiberglass, but also of other flexible fibers such as cotton, mineral wool, and sheep’s wool.