Macy's put solar panels on some store roofs, is working to cut energy use, recycling more and generally trying to "green up." But the department store still wants shoppers to use bags. Some bag, any bag.

"It is not necessarily a good thing for people to be walking out of a store with merchandise that's not in a bag," explained spokesman Jim Sluzewski. Sure, some people would rather forgo having their purchases put in a bag, but Mr. Sluzewski also believes customers wouldn't appreciate being stopped for a receipt check every time they leave a store.

So Macy's has come up with a compromise.

The chain will replace the 43 million or so laminated paper bags that it uses annually with a recyclable version made of 30 percent recycled materials. In addition, it will begin selling reusable cotton totes.

Retailers nationwide are moving to give environmentally active customers choices while fending off, as much as possible, government rules that would limit the industry's options. The shopping bag offers a particularly visible example of how different stores have moved quickly to tailor the growing green trends to fit.

A few years ago, the American bag seemed secure in its job, taking home goods and doing a little advertising work on the side. Debates were limited mainly to paper vs. plastic.

But environmentalists noted it takes hundreds of years for plastic to break down. People could see bags littering streets, and statistics showed only a small percentage making it to recycling. San Francisco passed rules to require use of compostable bags.

Rather than be forced to go that route, many retailers found other ways to answer the call for fewer bags on the planet.

Whole Foods Markets has been selling reusable bags for years but is now going a step further. The natural foods grocer is on track to stop using disposable plastic grocery bags in its 270 stores by today, a company spokeswoman said.

Swedish furniture chain Ikea will stop offering disposable plastic bags for purchase by October. The retailer started its phase-out last year by charging 5 cents for plastic bags and donating the proceeds to a forestry group. The company claimed it reduced U.S. plastic bag consumption from 70 million plastic bags to 35 million.

Shoppers at Wal-Mart, Target, Giant Eagle, Trader Joe's and many other groceries now see displays with reusable bags for sale. Discount grocer Aldi has long charged for disposable bags as part of its low-cost business model.

The deeper retailers get into the issues around the shopping bag, the more nuanced it can be. McGinnis Sisters specialty food stores introduced reusable bags made in China last summer. In March, the grocer with stores in Brentwood and Monroeville began offering more expensive versions made in the United States.

The concern was not just national pride but also the environmental costs of transporting bags. So far, consumers have purchased about 2,500 bags from China and 800 of the newer offerings. Jennifer R. Daurora, who handles business development for the stores, estimates at least 25 percent of customers bring a reusable bag.

Growing acceptance of such programs spurred state Rep. Lisa Bennington, a Democrat from Morningside, to introduce a bill that would phase out the use of nonbiodegradable plastic bags at large stores in Pennsylvania that carry groceries.

A week or so before the bill was scheduled for an early April committee hearing, lobbyists began contacting her. Letters came from groups such as the Progressive Bag Alliance, the American Chemistry Council, convenience store and food merchant groups, even massive retailer Wal-Mart.

Most of the lobbying letters expressed concern over the bill but indicated support for recycling, she said. "They want recycling. They're going to get recycling." Ms. Bennington now plans to offer an amendment that, instead of trying to stop use of noncompostable plastic bags, would mandate retailers offer at-store recycling programs.

Giant Eagle officials have said in the past that they evaluated using compostable bags but rejected them. Instead the company has been pushing recycling and reusable bags. Last year, the O'Hara grocer said it collected for recycling more than 1,200 tons of film plastic, much of which wasn't from bags, compared with 450 tons in 2006.

The company has sold several hundred thousand reusable bags since it began offering them in November 2006. This year, Giant Eagle put up posters promoting reusable bags. The signs were designed by students at Carnegie Mellon University.

Ms. Bennington's bill does not address bag use beyond large supermarkets and drugstores carrying grocery items. She noted the sheer volume of bags that consumers tend to pick up during a visit to the grocer typically exceeds that at most mall stores.

Putting recycling bins at the front entrance to a store such as Saks Fifth Avenue, Victoria's Secret or J.C. Penney might not fit the image that such retailers try to convey but, as the recent changes at Macy's show, the push to change shopping bags no longer stops at the mall doors.

Last weekend, the Mall at Robinson was one of 15 shopping centers owned by Cleveland-based Forest City Enterprises to give out reusable canvas tote bags to customers who brought plastic bottles to recycle.

After the promotion ended, the bags were to be sold at the guest services desk for $3 each. Any proceeds will go toward ordering more, said Shema Krinsky, director of marketing. "My hope is to offer them to our guests every day."

If there's enough activity on the part of retailers, they may be able to please the customers who focus on such things and cut bag use while avoiding too much governmental intervention on the issue.

Being flexible makes management's decisions easier. For example, Macy's will still use small plastic bags that seem to work best for items such as socks, jewelry and other small goods. Meanwhile, the retailer doesn't mind if customers bring reusable bags from other places.

There also is some leeway for individual stores on the department store chain's policy of getting merchandise into bags rather than letting customers just go bagless. "It's not necessarily a hard and fast policy," said Mr. Sluzewski.

In the end, he's not sure how many shoppers will decide to bring their own, rather than walk out with a new department store bag. "It does require you to remember to take them. But if it's important to customers, they'll do it."