This category of plastic packaging includes so much more than Polyethylene terephthalate (PET), the plastic used most commonly for soft drink bottles and other beverages. But a wide range of bottles—and even the closures used for PET bottles are made from other plastic resins. This is because the family of plastics is so versatile and varied. Different resins provide different properties and benefits. The closure for a PET beverage bottle is generally either polypropylene (PP) or low density polyethylene (LDPE). We rely on high density polyethylene for products like milk jugs. High density polyethylene for bottles to safely protect laundry detergent, fertilizers and a broad range of consumer goods.