Nonlatex clean room paper is impregnated with polyethylene and doesn't use organic fillers - paper is 100 percent recyclable. Paper is produced in an ISO Class 5 (formerly Class 100) environment and cleaned and double bagged in an ISO Class 4 (formerly Class 10) environment. Features excellent printability and heat Toner adhesion, with high opacity and durability. Notebooks feature high-density polyethylene covers, and are cleaned and packaged in an ISO Class 5 (formerly Class 100) environment. Polyethylene-binding technology reduces paper fiber and allows recycling