MILWAUKEE — Jeannette Wright constantly reuses plastic food containers, whether it's to carry snacks for her two young sons or store last night's dinner in the fridge.

That is, until they get dirty. Or she loses them. Then she simply buys more.

Gone are the days of putting your name on food storage containers or chasing down recipients of holiday cookies who have yet to return them. Wright, of West Allis, Wis., said it doesn't matter what happens to the containers because they cost only about $1 each. She figures she spends about $8 a month to keep her cabinets restocked.

"If I lose them, it's not a big deal because it's not like you spend a lot of money on them," said Wright, 33.

ALL WRAPPED UP

The food storage industry is huge, with Americans spending about $1.4 billion a year in the segment, which is dominated by plastic bags and includes plastic wrap, aluminum foil and wax paper.

While sales in the overall segment have flattened slightly, according to research firm Mintel, the disposable plastic container market has grown, with receipts at about $130 million in 2003, the last year for which figures were available. It's now approaching $200 million a year, with some 1 billion containers sold in the U.S. each year, said Raquel Beckett, senior brand manager for Ziploc containers with S.C. Johnson & Sons in Racine, Wis.

Manufacturers are racing to create more specialized products to further grow the market, crafting containers with tighter seals or seasonal colors, or adding interlocking lids so kitchen cabinets won't be so cluttered.

Consumers like the containers, analysts say, because they're sturdier than plastic bags and can hold liquids. They also cost less than offerings such as Tupperware, which popularized plastic food-storage kitchenware with its purchasing parties in the 1950s.

People originally didn't mind spending more on containers like Tupperware because they were primarily used in the home, said Marcia Mogelonsky, a research analyst at Mintel International. But as more women entered the work force, disposable products just made sense, she said. Consumers would get their money's worth after a few uses, so it was OK to forget them at the office or just toss them out rather than keep washing them, she said.

"We're in a rush. It's the convenience factor that's a major thing to drive this," she said. "It's not convenient to have to remember to bring your dirty dishes home."

FIRST CAME GLADWARE

Disposable containers were first introduced nationally by GladWare, a division of Oakland, Calif.-based Clorox Co. in 1998. Sales at the time were around $56 million, compared with $777 million for plastic food bags, according to Mintel.

Glad noticed that people were reusing items like retailers' cottage cheese and yogurt containers to store leftovers and other foods, and realized there was an unmet need, said Glad spokesman David Kellis.

"When you see consumers creating makeshift products — that's when you know there's an opportunity out there," he said.

Ed Tucker, an associate research fellow with Glad, came up with the idea for a disposable plastic container in the early 1990s. The secret to its success, Tucker said, was in the way it was produced, through a process called thermoforming. Large sheets of plastic are heated and formed over molds, which creates a lighter product, and does it more quickly than injecting plastic into molds. That process takes longer and creates a somewhat sturdier product, but one that is typically more expensive, he said.

The technology that goes into production is improving so much that the products have few usage issues and hold up ever better to heat and cold, said Beckett of SC Johnson, which also makes Saran plastic wrap and Windex cleaner.

With consumers already sold on the concept, container makers are differentiating themselves with more specialized products, such as Ziploc containers' new way of locking while twisting, Mogelonsky said. The GladWare product line is in its third generation of developments, including new lids that interlock.

"Whatever they can do to make it a more useful container, that's where the competition lies — in making it more useful, inexpensive and disposable," she said.

DO YOU OWN 62?

Sales peak around the holiday season, when people give food as gifts, and before school starts, when parents load up on containers for their children, Beckett said. The average family has about 62 disposable containers, many of those replacing sturdier products, she said.

"They're very close to long-life containers," Beckett said. "If you talk to consumers, there's little difference to them."

Other labels are also getting into the market, providing cheaper alternatives, she said, but the big brands will keep finding new developments. Manufacturers are now looking at ways to make the containers biodegradable, possibly by using corn-based products, Beckett said.

But for Wright, the suburban Wisconsin mother, price is key.

"I just go with whatever is on sale," she said.

Tupperware Brands Corp., the Orlando-based maker of Tupperware, hasn't considered making low-cost plastic containers because its products are known for their longevity, said CEO Rick Goings. Sales have not been affected, despite their relatively higher price — about $6 each — because people hang on to things they value, he said.

"I'm holding a disposable pen," Goings said. "I will lose two or three of these a week. But my better pens? I always know where they are."