For times when you don’t care if a plastic container gets lost, warped, or stained once it has served its immediate purpose, Gladware, Dixieware, and Ziploc make inexpensive versions you can use and toss. But, in fact — and worth noting, as these containers are not widely recyclable — they stand up surprisingly well to repeated use. Most are made from polypropylene (look for the number 5 in a triangle on the bottom), the same material used for Rubbermaid and other more permanent containers. The difference is in the weight of the plastic: The thicker walls of permanent containers provide a better barrier against moisture loss or gain and oxygen intrusion, says John Krochta, a plastics expert and a professor of food engineering at the University of California at Davis. Plus, the disposables’ thinner sides won’t take quite as much abuse (from dishwashers, microwaving, and general banging around) as their more durable counterparts will.