Modern cellulose insulation is made from 75 to 85 percent recycled paper or denim, treated with boric acid, borax, or ammonium sulfate.
Double bubble insulation consists of two layers of polyethylene bubbles between two metalized coatings, effectively preventing frost and condensation in various structures.
Attic insulation levels are measured by R-Value, which indicates resistance to heat flow. Most attics should be insulated to R-38, or about 10 to 14 inches, depending on the insulation type.