cotton batts
Flexible insulation sheets or pads made from cotton fibers or cloth, including industrial or recycled denim.
Cotton batts are sheets or pads of cloth or loose fibers made from the cotton plant. A common form of this is industrial or recycled scrap denim. Its thermal resistance varies by product and does not universally exceed fiberglass. Recycled fiber content can reduce the demand for new material. It can be difficult to cut, needs protection from moisture, and generally contains added flame retardants.
The cotton fibers or fabric form a batt that holds together as an insulating unit. Recycled denim is one source of that material rather than a separate insulation form.
Thermal resistance depends on the particular product and its thickness. Fire-retardant treatment and moisture conditions are separate from the cotton identity of the fibers.