There is a tendency to utilize underground space for the less ornamental purposes of civilization; there is the Metropolitan Railway in London, for instance, there are new electric railways, there are subways, there are underground workrooms and restaurants, and they increase and multiply.
Polystyrene can be naturally transparent, but can be colored with colorants. Uses include protective packaging (such as packing peanuts and CD and DVD cases), containers (such as clamshells), lids, bottles, trays, tumblers, and disposable cutlery.
3. packaging-material used to make packages. blister pack, bubble pack-packaging in which a product is sealed between a cardboard backing and clear plastic cover. material-things needed for doing or making something; writing materials; useful teaching materials.