Constructed of super heavy duty 6 mil black Low Density Polyethylene (LDPE) film. Opaque, all virgin poly is great for light-sensitive products. Neatly wound on a 3 core with 1 diameter core plug. Manufactured to exact specification to ensure even wall thickness. Can be heat sealed, tied, stapled or taped shut. See our Tubing Dispensers and Thermal Sealers for making your own custom static control bags.