KeepFresh 12" x 18" 2mil Plastic Poly Bags, Flat Low Density Polyethylene Bags, 100 Count Pack of 100 12"x18" Low Density Polyethylene (LDPE) Plastic Poly Bags. 2mil Bags most popular thickness for parts, clothing and food. Meets FDA and USDA specifications for food contact. 100% virgin, high clarity polyethylene film. LDPE bags are the most commonly used plastic bag because they provide excellent protection for everyday use at a great price.