You guessed right, denim insulation is made from old blue jeans. Like Roxul, Denim insulation uses a recycled product to make quality batting insulation. Similar to cellulose, it’s incredibly environmental. And like Roxul’s stone wool, denim insulation undergoes processing before it’s ready to use. Denim insulation’s environmental bonus even garnered the praise of the California Academy of Sciences. Their museum, which prides itself on sustainability, is insulated by 68% denim.