When Nestle SA launched its new Country Creamery ice cream a few weeks ago, one of the product's big selling points had nothing to do with chocolate or vanilla. It was its container.

Nestle designers spent nine months to come up with a plastic lid -- easier to pull off when the ice cream is frozen -- and ribbed carton corners -- easier to grip when scooping.The effort is part of a new companywide push at Nestle, the world's biggest food company, to make it easier for people to rip open its pouches, twist off its caps and reseal its tubs.

How a product is opened is a packager's priority. Containers need to be tight enough to withstand shipment to warehouses and stores, yet must open easily once consumers get the product home. And while packaging has long had to be tamper-resistant, governments, concerned about terrorist attacks on food, have urged companies to make their packaging even tougher.

Nestle research indicates that hard-to-open packs are among consumers' top complaints. Last year, Helmut Traitler, Nestle global head of packaging, ordered all his packaging engineers and designers around the world to find ways to solve the problem. Due to lengthy product-development cycles, the changes are hitting store shelves now.

"We knew that some of the new packaging out there could be almost unopenable," Mr. Traitler says.

Changes in how people eat and drink are also forcing companies to think harder about caps, seals and lids. Individual-size servings can be harder to open because there is less surface area to grip. The rise in snacking is prompting companies to come up with packaging that is easy to open while driving a car or walking down the street. And easy openings are key for two important target customer groups -- kids and aging baby boomers.

"My daughter has come home and said she's not been able to eat all her snacks because she couldn't open them," says Tracey Arneson, a 41-year-old mother of two in Cheshire, Conn. She started making a little tear in bags of graham crackers so that her 5-year-old daughter can open them without her teachers' help.

Nestle, based in Vevey, Switzerland, has packaging teams around the world, and each is required to present an inventory of improvements every quarter. Some are as simple as slightly deeper indentations in the flat end of candy wrappers in Brazil that make them easier to rip open, or deeper notches on single-serve packets of Nescafe in China. Nestle asked its suppliers to find a type of glue to make the clicking sound louder when the tube of its Smarties candies, the colorful chocolates popular with British children, opens. The company says it has introduced nearly 100 changes so far.

Nestle's biggest problem has been cost. The cost of packaging has soared this year along with the price of oil, a major ingredient in everything from water bottles to film wrap. For instance, Nestle saw prices for its plastic packaging rise by anywhere from 20 percent to 35 percent last year. Packaging can cost from less than 1 percent to as much as 15 percent of the overall cost to make a Nestle food or drink product. Resealable zip-lock plastic bags, popular with older people and busy moms, can add an average of 20 percent to packages such as pouches for pet food, says John Kleindouwel, sales and marketing director of flexible packaging for Amcor Ltd., a packaging supplier to Kraft Foods Inc., Procter & Gamble Co. and Nestle.

For its packaging, Nestle, like most consumer-products companies, relies heavily on outside suppliers who work with its in-house designers and brand managers. Mr. Traitler has told the packaging teams that, wherever possible, they have to make changes without increasing costs. Nestle, which had 2004 sales of more than $65 billion, spends almost $6 billion a year on packaging.

When Nestle floated the idea of dropping its expensive flip-top sports cap on its Italian bottled water brand Acqua Panna and using a regular -- and cheaper -- screw cap instead, women in focus groups said they would be less likely to buy the water without the sports cap. So Nestle raised the price of its water by about 7 percent to about 55 cents for a 75-centiliter (1.65-pint) bottle from about 51 cents this year to cover the extra cost of the sports cap. Sales haven't suffered, says Lorenzo Potecchi, head of Nestle's retail water business in Italy.

Consumers are quick to complain about problems with a package top, Nestle has discovered. Nescafe marketing manager Marty Sharkey spent two years testing a new push-button lid before launching a revamped jar for Nescafe Taster's Choice coffee in 2004. But calls to Nestle's toll-free number surged, two-thirds of which were complaints about the lid. About half of Taster's Choice consumers are age 55 and up, and many were having trouble getting the lid to open, Nestle says.

Nestle softened the spot where consumers press the button and shortened the latch inside the cap. It branded the new closure a "Fresh Click" lid and replaced a recipe for cafe au lait on the side of the jar with the new "Fresh Click" logo showing two thumbs opening the lid. It sent the new seven-ounce jar, which hit the shelves this past June, to thousands of consumers who had complained.

To pay for the change, Nestle cut costs for other promotions. "Your most loyal consumers represent 70 percent of your volume," says Mr. Sharkey. "You'll find the money to keep that group satisfied."

Michelle Arnau, a marketing manager for Nestle's PowerBar brand, stood at mile 17 of the 2004 New York City Marathon to see how runners were using PowerGel, a concentrated, single-serve gel that athletes use to boost endurance. She saw that runners typically tore off the top with their teeth and wanted to squeeze it out in one shot so that they didn't break their stride. To her dismay, the long neck of the pack sometimes prevented the gel from oozing out quickly. "We were seeing multiple squeezings happening," Ms. Arnau says.

Nestle designers went back to the drawing board, eventually settling on an upside-down triangular shaped top that is narrow enough to control the flow but also fits into the athlete's mouth. It's scheduled to hit shelves next year.

Another evolving Nestle product is Dibs, ice-cream bonbons in a carton. Brand manager Suzanne Ginestro had spent more than a year looking for ways to make the lid of its oval carton easy to pry off -- essential because Nestle wanted consumers to see the product as an eat-on-the-go snack.

Ms. Ginestro tried plastic tabs that let the lid snap off. But focus groups were confused. She changed the lid's color from red to orange to set it apart from the red carton. She made the smooth tab ribbed and loosened the tab to make it pop off easily. Focus groups still complained. "We decided that we were going to have to start from scratch," says Ms. Ginestro.

Nestle finally settled on a paperboard lid -- just like the one on most ice-cream containers. It plans to roll out the new packaging in the spring.