Amanda Fain pulled pair after pair of old blue jeans from a cardboard box and folded them to get ready for shipment to a recycling plant.

Some of the jeans were so much out of style that Fain couldn't help but laugh, but she was glad to have them.

Fain is the customer service manager at the Gap store at EastChase, and the jeans are part of the chain's national collection effort. Customers who bring in their worn denim will get 30 percent off new jeans. The used denim eventually will become insulation for homes in disadvantaged communities.

The store started collecting denim items last week and will continue to do so through Sunday.

Fain said coupons are available, but most customers chose to redeem the discount immediately. Each denim item earns a discount on one pair of jeans.

Many of the jeans she pulled from the box were purchased from a Gap store, but she said the chain is giving the discount on all denim. And it doesn't have to be jeans.

"We will take jackets, shirts and even overalls," she said. "I even had one person say she was going to bring in scraps from an art project."

Signs throughout the store promote the discount, but Fain said store employees make sure anyone trading in the denim knows how it will be used.

Shoppers trading in denim brought in enough to fill a store display box in just three days, and Fain said she hopes to fill it several more times before the promotion ends.

It is all part of Cotton Inc.'s From Blue to Green program. According to the organization, about 500 pairs of recycled jeans will provide enough cotton insulation for a typical home.

This is the first year Gap has participated in the program, which collected 180,000 pieces, enough for about 360 homes, in 2009.