Below is a list of Plastic Packaging manufacturers from Monrovia, California. Plastic packaging encompasses all storage or containment devices produced through the manipulation of any number of polymer resins. While the term 'plastics' applies to a diverse group of materials, they are in general light weight, durable and inexpensive to produce. For these reasons and more, as much as 53% of all packaged goods are contained in plastics. Because plastics can also be made clear, they are ideal for easy product display and identification as well.