– When Julie Ghatan opened Dovetail in 2008, she could tell when customers entered her boutique in Chicago’s Noble Square neighborhood without realizing much of the clothing and accessories were vintage, not new merchandise.

“You could just see it click on their faces,” she said. They’d walk right back out.”

That doesn’t happen anymore. Buying secondhand, once stigmatized, is going mainstream. And here’s how you can tell: Department stores want in on it.

Shoppers like the thrill of scoring a deal or one-of-a-kind find, or want to shop without worrying about the apparel industry’s environmental effect. Others are both buyers and sellers, knowing each bargain purchase can be resold to make space in their wallet and closet for something new.

“It’s better for the environment, my wallet and morals,” said Izzy Howard, 24, shopping recently at Crossroads Trading in Wicker Park, a Chicago neighborhood.

Attitudes toward secondhand shopping started shifting during the recession, when “it became chic to get a good deal,” said Oliver Chen, a retail analyst at Cowen & Co.

More than a decade later, it’s proving to be more than a passing trend. Over the past five years, stores selling used merchandise have grown faster than traditional apparel retailers, not counting discount and off-price chains, said David Weiss, a partner at Chicago-based consulting firm McMillanDoolittle. Even traditional retailers like J.C. Penney and Macy’s are experimenting with selling secondhand apparel.

“This isn’t a fad that’s going to disappear anytime soon. This is a generational shift,” Weiss said.

It may be multigenerational.

When Linda Beckstrom, 64, of Chicago, was younger, resale shopping meant trips to disorganized stores without fitting rooms that forced shoppers to try on clothes in the aisles. Today, she looks for bargains at stores like Buffalo Exchange, on a stretch of Milwaukee Avenue in Wicker Park with several vintage and resale shops.

“When the clothes are expensive, you can’t have as much fun, and sometimes the clothes here are more interesting than the cookie-cutter stuff you see in Target,” she said.

Online, there are sites for every niche. Sellers who don’t want to handle transactions themselves can ship goods to companies that operate like virtual consignment or thrift stores.

At the luxury end, the RealReal deals in authenticated luxury goods, while ThredUp accepts a wide range of brands found at a typical mall.

Others let customers buy and sell directly from each other, like eBay, Poshmark, Etsy, Depop and Facebook Marketplace.

Traditional brands and retailers are joining too. Patagonia gives customers store credit for quality used gear the brand can resell.

Macy’s and J.C. Penney are each putting some ThredUp merchandise in a few dozen stores, including Macy’s stores.

In-store partnerships help San Francisco-based ThredUp reach customers who want to touch and feel merchandise before buying, spokeswoman Samantha Blumenthal said in an e-mail. The company started in 2009 as a place to swap men’s apparel but now focuses on women’s and kids’ clothing.

That’s a lot of new competition among online and brick-and-mortar thrift, vintage and consignment shops, both for customers and for sellers.

But local secondhand stores said they have a couple things going for them. One, shoppers tend to be less confident in an item’s fit and condition when buying secondhand, making them even more eager to try something in person before buying. And second, some stores see new players as gateways that could bring in even more customers.

Some consignment and thrift stores have begun selling online themselves. The wider audience generally brings in higher prices, especially for frequently searched brands and designers, said Cindi Dibuglione, owner of Cynthia’s Consignments, who has been selling on eBay since 1995 and has employees dedicated to online sales.

Other store owners said they use social media to drive sales but found selling online to be more effort than it was worth, except for more expensive items that need a broader pool of customers.

“I’d rather have someone come in and have a great experience,” said Sasha Hodges, co-owner of Kokorokoko Vintage in Wicker Park, which specializes in ‘80s and ‘90s apparel and accessories.

At least some of those customers are hoping to make a quick buck themselves. Hodges said she can tell when customers are buying something to wear and when they’re just angling for a profit online.

“In the last couple years I have felt there’s more of the ‘Is this valuable, can I flip this?’ vs. ‘Oh, I like this and know it’s cool,’ “ Hodges said.

Apps and websites that let consumers list their own merchandise and set their own price might bring a higher payout than working with a thrift store, but require artfully composed pictures, descriptions crafted to pop up in search results and haggling with buyers.

Emma Cullen, 26, successfully sold a few Adidas items on Depop but struggled to get buyers interested in smaller brands. When she needed to clear out her closet before an upcoming move, she went to Crossroads, which buys on the spot.

As online resale options grow, it could be difficult for brick-and-mortar resale shops to compete against their sheer scale, said Chen, the retail analyst.

“If you’re a customer, do you go visit that store, or do you go online and see thousands and thousands of products?” he said.